Re: [mailop] Maximum message size - tag along question.

[Brandon Long via mailop]

We choose our limits based on the base64 size and message that to the user,
ie we say we handle
25MB attachments and set the message size limit at 4/3*25 + some overhead.

For most users, trying to explain the differences is not useful.

Brandon

On Fri, Oct 23, 2020 at 10:43 PM Grant Taylor via mailop 
wrote:

> Do you take into account the 4/3 inflation with Base64 encoding and / or
> allow for any message body when setting the maximum message size that
> your servers allow?
>
>
>
> --
> Grant. . . .
> unix || die
>
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Re: [mailop] Maximum message size

[Brandon Long via mailop]

On Sun, Oct 25, 2020 at 5:19 PM Ángel via mailop  wrote:

> On 2020-10-24 at 14:38 +0100, Andrew C Aitchison via mailop wrote:
> > How reliable is the SIZE value in the EHLO response ?
>
> I would say it's reliable on how much they are able to receive.
> Although it doesn't mean they are willing to send messages that big.
>
> I was in the same boat as Adam a few months ago, and I reviewed the
> sizes of common providers so I could reach an adequate size. I found
> that big providers like Gmail offered big email sizes (150MB) but
> actually automatically converted attachments larger than ~30MB into
> Google Drive links when using the webmail interface. So the large size
> stated on SIZE was a bit misleading.
>

Different mailboxes have different limits, so the EHLO SIZE value is the
maximum for any mailbox.

If you try to send larger than a specific mailbox can handle, it will be
rejected, hopefully at RCPT TO time if
the sending server supports RFC 1870.

OTOH, very few mailboxes support higher than the 50MB size, so in that
sense it is misleading but that's the
limits of the protocol.

Brandon
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Re: [mailop] Maximum message size

[Alessandro Vesely via mailop]

On Sat 24/Oct/2020 01:35:04 +0200 Jaroslaw Rafa via mailop wrote:

(In one of the places I worked previously, we tried to create our own poor
man's "sendfile" replacement, by plugging a mail filter into a MTA, which
removed from submitted messages attachments larger than a certain size,
stored them on a webserver with randomly generated links, and put these
links in outgoing message instead of removed attachments. The recipient
could download the original file by clicking on a link received in the
message. That's of course a very primitive approach, as the real
implementation would have to be in the MUA).



To let a MUA know that an URL points to content to be downloaded as part of the 
message, one could use:


Content-type: message/external-body; access-type=URL; URL="scheme:whatever"

RFC 2017 provided for URL schemes "FTP", "ANON-FTP", "TFTP", "LOCAL-FILE", and 
"MAIL-SERVER" (the same access-types defined by RFC 2046.)


Never saw a MUA supporting that.  Are there any?



Best
Ale
--













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Re: [mailop] Maximum message size

[Ángel via mailop]

On 2020-10-24 at 14:38 +0100, Andrew C Aitchison via mailop wrote:
> How reliable is the SIZE value in the EHLO response ?

I would say it's reliable on how much they are able to receive.
Although it doesn't mean they are willing to send messages that big.

I was in the same boat as Adam a few months ago, and I reviewed the
sizes of common providers so I could reach an adequate size. I found
that big providers like Gmail offered big email sizes (150MB) but
actually automatically converted attachments larger than ~30MB into
Google Drive links when using the webmail interface. So the large size
stated on SIZE was a bit misleading.

Regards

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Re: [mailop] Maximum message size

[Hans-Martin Mosner via mailop]

Am 24.10.20 um 19:19 schrieb John Levine via mailop:
>
> FTP was swell forty years ago but it's obsolete now. Nothing,
> including the user names or passwords, is encrypted, and it needs to
> set up a second TCP connection for each data transfer which confuses
> NATs and firewalls.
>
> There are better alternatives now, of course. scp and sftp which run
> over ssh seem to be the ones of choice although they don't have the
> anonymous option that FTP does.
>
>> automatically and transparently to the user, given only recipient's email
>> address - that's the way "sendfile" worked.
> Wow, what a spammer's dream, drop my malware right into the victim's folder.
>
scp and sftp are also relatively cumbersome. Services like dropbox etc. are 
acceptable form a UX perspective (in my
opinion) as they work through the omnipresent browser interface, but their 
privacy is pretty weak.

However, it's really easy for an organization to set up a server with ownCloud 
or Nextcloud to enable their users to
store files and send download links in their mails. Browser access using TLS 
ensures both transport privacy as well as
the ability to verify that a file is being provided by the organization of the 
mail sender.

The private cloud options enable both anonymous download (by publicly providing 
links to a file or directory) as well as
anonymous upload (by providing links to a directory into which can files be 
dropped).

I know that many companies are not willing or able to set up their own 
co-located or rented server, and in such cases
using public cloud storage services with encrypted files may be an option. 
However, this requires more cooperation by
the users to ensure confidentiality of documents.

Cheers,
Hans-Martin


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Re: [mailop] Maximum message size

[John Levine via mailop]

In article <20201024112039.ga5...@rafa.eu.org>,
Jaroslaw Rafa via mailop  wrote:
>Dnia 24.10.2020 o godz. 01:36:08 Kenneth Porter via mailop pisze:
>> 
>> The biggest problem with getting business partners to use FTP is
>> that they're often not allowed to use 3rd party software (like
>
>In my opinion, the biggest problem to use FTP is that it requires several
>steps which are not quite intuitive for inexperienced user.

FTP was swell forty years ago but it's obsolete now. Nothing,
including the user names or passwords, is encrypted, and it needs to
set up a second TCP connection for each data transfer which confuses
NATs and firewalls.

There are better alternatives now, of course. scp and sftp which run
over ssh seem to be the ones of choice although they don't have the
anonymous option that FTP does.

>automatically and transparently to the user, given only recipient's email
>address - that's the way "sendfile" worked.

Wow, what a spammer's dream, drop my malware right into the victim's folder.

-- 
Regards,
John Levine, jo...@taugh.com, Primary Perpetrator of "The Internet for Dummies",
Please consider the environment before reading this e-mail. https://jl.ly

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Re: [mailop] Maximum message size

[Andrew C Aitchison via mailop]

On Sat, 24 Oct 2020, Sidsel Jensen via mailop wrote:


On 23 Oct 2020, at 20.08, Michael Peddemors via mailop  
wrote:

By default we still distribute with a 10MG maximum size, but frankly almost all 
of our customers has bumped it to the maximum we recommend, which is 20MG.  
(the odd one even went to 30, but we don't recommend that)

Too bad this isnt' escalated to a recommended standard.

How about we use this as a chance to discuss this with other groups such as 
M3AAWG and IETF, to try to come up with a written consensus for others to 
follow.. (I think gmail still has the 25MG max size, but someone can correct me 
on that)



Hi Michael

Looks like nobody answered you on that point regarding discussion of and 
finding some sort of consensus on the size limits on mails.
I for one, think it sounds like a good idea for a discussion point in M3AAWG 
and/or IETF. *thumbs up*

The result for us, is that we have fx. specific error msgs for customers adding 
attachments which are above the limits for fx. what Hotmail and Microsoft 
accepts.

Result: "550 5.7.1 Message size 95566050b too big for delivery to hotmail.com 
(31457280b max)" (in 00:00:00.005)
Result: "550 5.7.1 Message size 32635093b too big for delivery to live.nl (31457280b 
max)" (in 00:00:00.002)
Result: "550 5.7.1 Message size 41809588b too big for delivery to live.se (31457280b 
max)" (in 00:00:00.002)

- right now it’s a manual task to maintain and review these once in a while.
(Aka a pet - not cattle…) Sounds like others have a similar problem.


How reliable is the SIZE value in the EHLO response ?

--
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Re: [mailop] Maximum message size

[Suresh Ramasubramanian via mailop]

“be conservative in what yoyu send and generous in what you accept” has its 
uses when you separate your inbound and outbound mtas. Discuss.

From: mailop  on behalf of Sidsel Jensen via mailop 

Reply to: Sidsel Jensen 
Date: Saturday, 24 October 2020 at 5:50 PM
To: mailop 
Subject: Re: [mailop] Maximum message size

On 23 Oct 2020, at 20.08, Michael Peddemors via mailop 
mailto:mailop@mailop.org>> wrote:

By default we still distribute with a 10MG maximum size, but frankly almost all 
of our customers has bumped it to the maximum we recommend, which is 20MG.  
(the odd one even went to 30, but we don't recommend that)

Too bad this isnt' escalated to a recommended standard.

How about we use this as a chance to discuss this with other groups such as 
M3AAWG and IETF, to try to come up with a written consensus for others to 
follow.. (I think gmail still has the 25MG max size, but someone can correct me 
on that)

Hi Michael

Looks like nobody answered you on that point regarding discussion of and 
finding some sort of consensus on the size limits on mails.
I for one, think it sounds like a good idea for a discussion point in M3AAWG 
and/or IETF. *thumbs up*

The result for us, is that we have fx. specific error msgs for customers adding 
attachments which are above the limits for fx. what Hotmail and Microsoft 
accepts.

Result: "550 5.7.1 Message size 95566050b too big for delivery to 
hotmail.com<http://hotmail.com> (31457280b max)" (in 00:00:00.005)
Result: "550 5.7.1 Message size 32635093b too big for delivery to 
live.nl<http://live.nl> (31457280b max)" (in 00:00:00.002)
Result: "550 5.7.1 Message size 41809588b too big for delivery to 
live.se<http://live.se> (31457280b max)" (in 00:00:00.002)

- right now it’s a manual task to maintain and review these once in a while.
(Aka a pet - not cattle…) Sounds like others have a similar problem.

I believe our limit right now is 100MB.

Kind Regards,
Sidsel Jensen
Team manager Mail & Abuse, Systems Engineer @ One.com<http://One.com>


On 2020-10-23 10:48 a.m., Evert Mouw via mailop wrote:

On 10/23/20 7:23 PM, Adam Moffett via mailop wrote:

I'm at 200MB maximum message size and have someone requesting we increase that 
limit.

Is there any current consensus on what it should be?
Current default max. message size for Postfix configurations:
message_size_limit (default: 1024) / The maximal size in bytes of a 
message, including envelope information.
http://www.postfix.org/postconf.5.html
Also Microsoft Exchange 2019 has a default limit of 10 MB.
https://docs.microsoft.com/en-us/exchange/mail-flow/message-size-limits?view=exchserver-2019
Increase the limit all you want but don't expect other parties to accept or 
deliver large messages. I would not increase, but DEcrease the limit in your 
case. Learn the user to use other file transfer methods, or if you like 
Thunderbird, check this:
https://support.mozilla.org/en-US/kb/filelink-large-attachments
Regards, Evert
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Re: [mailop] Maximum message size

[Sidsel Jensen via mailop]

> On 23 Oct 2020, at 20.08, Michael Peddemors via mailop  
> wrote:
> 
> By default we still distribute with a 10MG maximum size, but frankly almost 
> all of our customers has bumped it to the maximum we recommend, which is 
> 20MG.  (the odd one even went to 30, but we don't recommend that)
> 
> Too bad this isnt' escalated to a recommended standard.
> 
> How about we use this as a chance to discuss this with other groups such as 
> M3AAWG and IETF, to try to come up with a written consensus for others to 
> follow.. (I think gmail still has the 25MG max size, but someone can correct 
> me on that)
> 

Hi Michael

Looks like nobody answered you on that point regarding discussion of and 
finding some sort of consensus on the size limits on mails.
I for one, think it sounds like a good idea for a discussion point in M3AAWG 
and/or IETF. *thumbs up*

The result for us, is that we have fx. specific error msgs for customers adding 
attachments which are above the limits for fx. what Hotmail and Microsoft 
accepts.

Result: "550 5.7.1 Message size 95566050b too big for delivery to hotmail.com 
(31457280b max)" (in 00:00:00.005)
Result: "550 5.7.1 Message size 32635093b too big for delivery to live.nl 
(31457280b max)" (in 00:00:00.002)
Result: "550 5.7.1 Message size 41809588b too big for delivery to live.se 
(31457280b max)" (in 00:00:00.002)

- right now it’s a manual task to maintain and review these once in a while.
(Aka a pet - not cattle…) Sounds like others have a similar problem.

I believe our limit right now is 100MB.

Kind Regards,
Sidsel Jensen
Team manager Mail & Abuse, Systems Engineer @ One.com 
> On 2020-10-23 10:48 a.m., Evert Mouw via mailop wrote:
>> On 10/23/20 7:23 PM, Adam Moffett via mailop wrote:
>>> I'm at 200MB maximum message size and have someone requesting we increase 
>>> that limit.
>>> 
>>> Is there any current consensus on what it should be?
>>> 
>> Current default max. message size for Postfix configurations:
>> message_size_limit (default: 1024) / The maximal size in bytes of a 
>> message, including envelope information.
>> http://www.postfix.org/postconf.5.html
>> Also Microsoft Exchange 2019 has a default limit of 10 MB.
>> https://docs.microsoft.com/en-us/exchange/mail-flow/message-size-limits?view=exchserver-2019
>> Increase the limit all you want but don't expect other parties to accept or 
>> deliver large messages. I would not increase, but DEcrease the limit in your 
>> case. Learn the user to use other file transfer methods, or if you like 
>> Thunderbird, check this:
>> https://support.mozilla.org/en-US/kb/filelink-large-attachments
>> Regards, Evert
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Re: [mailop] Maximum message size

[Jaroslaw Rafa via mailop]

Dnia 24.10.2020 o godz. 01:36:08 Kenneth Porter via mailop pisze:
> 
> The biggest problem with getting business partners to use FTP is
> that they're often not allowed to use 3rd party software (like

In my opinion, the biggest problem to use FTP is that it requires several
steps which are not quite intuitive for inexperienced user. You have first
to use FTP to put file on the server, then send the info about file's
location to the recipient and the recipient has again to use FTP to get the
file from server. I am thinking about something that does these operations
automatically and transparently to the user, given only recipient's email
address - that's the way "sendfile" worked.
-- 
Regards,
   Jaroslaw Rafa
   r...@rafa.eu.org
--
"In a million years, when kids go to school, they're gonna know: once there
was a Hushpuppy, and she lived with her daddy in the Bathtub."
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Re: [mailop] Maximum message size

[Kenneth Porter via mailop]

--On Saturday, October 24, 2020 2:35 AM +0200 Jaroslaw Rafa via mailop 
 wrote:



Why nobody ever tried to write a RFC for something like
"sendfile" and implement it in MUAs?


There was discussion recently on the Internet History list about FTP and 
how  it used to be how email was done before the rise of other email 
protocols. You composed a message and dropped it in the other user's mail 
directory. Headers came later as the routing system got more complicated.


See the thread "FTP RIP" here:



The biggest problem with getting business partners to use FTP is that 
they're often not allowed to use 3rd party software (like FileZilla) and 
the stock Microsoft command line FTP client is pretty lame and can't do 
secure transfers. I tried using DAV for awhile, but the MS DAV client 
didn't work well with the DAV server module in Apache.


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Re: [mailop] Maximum message size - tag along question.

[Mark Foster via mailop]

My usual limit is 100MB and then I explain to my users that:

1) That's the _email size limit_ and not the size limit for an attachment to an 
email
2) Email is inefficient when used for transferring files, thus overhead
3) Email is not intended to be a system for routinely moving large files
4) You can't garuntee what other mail servers in the chain may have enabled as 
maximum size limits, so upping the local limit isn't going to solve all your 
problems
5) Look at OneDrive, Dropbox or Google Drive as readily available ad-hoc file 
transfer options.

At 100MB I hear very few complaints. I certainly wouldn't be making the limit 
any higher for the OP's scenario.

Some legacy mail systems I have to deal with, struggle with the combination of 
large email + large number of recipients (when processing rules require you to 
bifurcate the email into one-email-per-recipient in order to enable 
per-recipient rule handling, your single 100MB email can become several 
gigabytes of processing) so that's another potential factor.

Mark.

-Original Message-
From: mailop  On Behalf Of Grant Taylor via mailop
Sent: Saturday, 24 October 2020 6:37 pm
To: mailop@mailop.org
Subject: [mailop] Maximum message size - tag along question.

Do you take into account the 4/3 inflation with Base64 encoding and / or allow 
for any message body when setting the maximum message size that your servers 
allow?



--
Grant. . . .
unix || die


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[mailop] Maximum message size - tag along question.

[Grant Taylor via mailop]

Do you take into account the 4/3 inflation with Base64 encoding and / or 
allow for any message body when setting the maximum message size that 
your servers allow?




--
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unix || die



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Re: [mailop] Maximum message size

[Jaroslaw Rafa via mailop]

Dnia 23.10.2020 o godz. 22:48:42 Adam Moffett via mailop pisze:
> 
> An additional argument is how much support labor is it worth to
> guide/force/teach the use of cloud storage compared to the risks of
> allowing larger emails?  One of these is things is way easier.
> Someday I may bow to the needs of ignorance because it's easier.

I always wondered, why - as it seems - noone ever tried to standardize and
get implemented Internet-wide a service that existed in the old academic
Bitnet/EARN network. In that network, each user account was associated with
two types of default inboxes: a mail inbox and a file inbox. Complementary
to the email service, which worked almost the same as Internet email (RFC822
style message format, etc.) - although it was plain text only, MIME didn't
yet exist at that time - there was another service called "sendfile", used to
send arbitrary files to the recipient. Both services used recipient's
e-mail address to send, mail messages arrived in mail inbox, and files
arrived in file inbox (which was something like a special directory in the
filesystem, and you could just copy the files from there). That was simple
to use and worked. Why nobody ever tried to write a RFC for something like
"sendfile" and implement it in MUAs?

(In one of the places I worked previously, we tried to create our own poor
man's "sendfile" replacement, by plugging a mail filter into a MTA, which
removed from submitted messages attachments larger than a certain size,
stored them on a webserver with randomly generated links, and put these
links in outgoing message instead of removed attachments. The recipient
could download the original file by clicking on a link received in the
message. That's of course a very primitive approach, as the real
implementation would have to be in the MUA).
-- 
Regards,
   Jaroslaw Rafa
   r...@rafa.eu.org
--
"In a million years, when kids go to school, they're gonna know: once there
was a Hushpuppy, and she lived with her daddy in the Bathtub."
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Re: [mailop] Maximum message size

[Thomas Walter via mailop]

On 24.10.20 00:48, Adam Moffett via mailop wrote:
> Nail on head Brandon.
> 
> An additional argument is how much support labor is it worth to
> guide/force/teach the use of cloud storage compared to the risks of
> allowing larger emails?  One of these is things is way easier.  Someday
> I may bow to the needs of ignorance because it's easier.
I am pretty sure none of your users sends encrypted emails, do they?
Inside of a company perhaps, but between different ones? Usually not.
Explaining that is a lot more difficult than having a file exchange
system in whatever form.

(BTW still the easiest way to get an unencrypted text or unprotected zip
file is to just tell them you can't open it.)

Then there's the issue of the law defining retention times, audit
compliant storage, backups and such for business communication which
does get a lot more difficult if big files are involved.

Besides email transports not being made for file transfer, the storage
mechanisms of MUAs aren't made for big files either.

Email is for sending letters, let DHL handle the bigger boxes.

Regards,
Thomas Walter

-- 
Thomas Walter
Datenverarbeitungszentrale

FH Münster
- University of Applied Sciences -
Corrensstr. 25, Raum B 112
48149 Münster

Tel: +49 251 83 64 908
Fax: +49 251 83 64 910
www.fh-muenster.de/dvz/



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Re: [mailop] Maximum message size

[Adam Moffett via mailop]

Nail on head Brandon.

An additional argument is how much support labor is it worth to 
guide/force/teach the use of cloud storage compared to the risks of 
allowing larger emails?  One of these is things is way easier.  Someday 
I may bow to the needs of ignorance because it's easier.


And I grudgingly admit that there's a convenience to having a document 
in your email alongside the communications related to it.  If the user 
can remember the name of a person on the email thread or some part of 
the subject or body text then they can search for the file and expect to 
find it.  Email was never intended to be a document storage/retrieval 
system, but somehow it ended up being fairly good at that at all the 
same.  I'm sure we can name eleventy-one groupware systems that cover 
this use case better, but email did it accidentally, for free, and with 
worldwide adoption and compatibility.   (BTW: *I* don't store my 
documents in my email.  I'm just saying I understand why people do)


-Adam


-- Original Message --
From: "Brandon Long via mailop" 
To: "Thomas Walter" 
Cc: "mailop" 
Sent: 10/23/2020 5:30:00 PM
Subject: Re: [mailop] Maximum message size

As much as we all may laugh at using email for these things, there are 
a bunch of benefits to it.  For example, telling someone at a company 
to use some random external service to host their potentially 
confidential material is not a great sell and probably against the 
rules at most large companies with security policies.  It also doesn't 
require everyone to get new logins or share urls that have no ACLs.


We've long had a request from enterprise for larger sizes, even though 
we also have Drive and our email apps push you to sharing large files 
via drive.  CAD files, genetic files, in-progress videos for ads and 
such, there's a lot of things that people would rather use.  Heck, 
sharing photos via email is still very popular, and as their sizes 
increase there's going to be more pressure for larger message sizes.


I agree that Email as a protocol may not be best for larger messages... 
but the fact that the users want it isn't wrong either.


Brandon

On Fri, Oct 23, 2020 at 2:21 PM Thomas Walter via mailop 
 wrote:



On 23.10.20 22:51, Jay Hennigan via mailop wrote:
> Perhaps someone should come up with a protocol designed to transfer
> files. They could name it File Transfer Protocol and abbreviate it 
FTP.


I'd prefer something with "Secure" in it's name though, preferably in
the front, so it shows the importance of it.

Regards,
Thomas Walter

--
Thomas Walter
Datenverarbeitungszentrale

FH Münster
- University of Applied Sciences -
Corrensstr. 25, Raum B 112
48149 Münster

Tel: +49 251 83 64 908
Fax: +49 251 83 64 910
www.fh-muenster.de/dvz/

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Re: [mailop] Maximum message size

[Brandon Long via mailop]

As much as we all may laugh at using email for these things, there are a
bunch of benefits to it.  For example, telling someone at a company to use
some random external service to host their potentially confidential
material is not a great sell and probably against the rules at most large
companies with security policies.  It also doesn't require everyone to get
new logins or share urls that have no ACLs.

We've long had a request from enterprise for larger sizes, even though we
also have Drive and our email apps push you to sharing large files via
drive.  CAD files, genetic files, in-progress videos for ads and such,
there's a lot of things that people would rather use.  Heck, sharing photos
via email is still very popular, and as their sizes increase there's going
to be more pressure for larger message sizes.

I agree that Email as a protocol may not be best for larger messages... but
the fact that the users want it isn't wrong either.

Brandon

On Fri, Oct 23, 2020 at 2:21 PM Thomas Walter via mailop 
wrote:

>
>
> On 23.10.20 22:51, Jay Hennigan via mailop wrote:
> > Perhaps someone should come up with a protocol designed to transfer
> > files. They could name it File Transfer Protocol and abbreviate it FTP.
>
> I'd prefer something with "Secure" in it's name though, preferably in
> the front, so it shows the importance of it.
>
> Regards,
> Thomas Walter
>
> --
> Thomas Walter
> Datenverarbeitungszentrale
>
> FH Münster
> - University of Applied Sciences -
> Corrensstr. 25, Raum B 112
> 48149 Münster
>
> Tel: +49 251 83 64 908 <+49%20251%208364908>
> Fax: +49 251 83 64 910 <+49%20251%208364910>
> www.fh-muenster.de/dvz/
>
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Re: [mailop] Maximum message size

[L. Mark Stone via mailop]

We use 100MB max message size, have customers who routinely send messages with 
attachments approaching that limit, and only rarely do we see a message 
rejected due to it being too large. 

Hope that helps, 
Mark 
___ 
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North America's Leading Zimbra VAR/BSP/Training Partner 
For Companies With Mission-Critical Email Needs 
Need more email security & compliance? Ask me about Mimecast! 



From: "Suresh Ramasubramanian via mailop"  
To: "Adam Moffett" , mailop@mailop.org 
Sent: Friday, October 23, 2020 1:51:08 PM 
Subject: Re: [mailop] Maximum message size 

Most if not all places ask that you use a file sharing solution - google drive, 
box etc for large files. 

--srs 

From: mailop  on behalf of Adam Moffett via mailop 
 
Sent: Friday, October 23, 2020 11:17:00 PM 
To: mailop@mailop.org  
Subject: Re: [mailop] Maximum message size 
Yes, it was set to 200MB years ago by request of an engineer sending CAD files. 
Now I have someone else who wants it larger. 

Meanwhile I have found in Google searching that GMail allows 25MB and I believe 
O365 is 150MB max. 

My initial impulse was to say no to this request because I'm aware of the DOS 
possibilities with large email sizes, but I thought I'd ask the community to 
see if I'm behind the times on what we think is too large. 



-- Original Message -- 
From: "Suresh Ramasubramanian" < [ mailto:ops.li...@gmail.com | 
ops.li...@gmail.com ] > 
To: "Adam Moffett" < [ mailto:a...@plexicomm.net | a...@plexicomm.net ] >; " [ 
mailto:mailop@mailop.org | mailop@mailop.org ] " < [ mailto:mailop@mailop.org | 
mailop@mailop.org ] > 
Sent: 10/23/2020 1:39:06 PM 
Subject: Re: [mailop] Maximum message size 




How many providers are going to accept 200 mb emails if you enable this and 
someone then tries to send one out? 

--srs 

From: mailop < [ mailto:mailop-boun...@mailop.org | mailop-boun...@mailop.org ] 
> on behalf of Adam Moffett via mailop < [ mailto:mailop@mailop.org | 
mailop@mailop.org ] > 
Sent: Friday, October 23, 2020 10:53:51 PM 
To: [ mailto:mailop@mailop.org | mailop@mailop.org ] < [ 
mailto:mailop@mailop.org | mailop@mailop.org ] > 
Subject: [mailop] Maximum message size 
I'm at 200MB maximum message size and have someone requesting we increase that 
limit. 

Is there any current consensus on what it should be? 


-- Adam Moffett, Network Engineer 
Plexicomm - Internet Solutions | [ 
https://mail.missioncriticalemail.com/www.plexicomm.net | www.plexicomm.net ] 
Office: 1.866.759.4678 x104 





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Re: [mailop] Maximum message size

[Suresh Ramasubramanian via mailop]

Most if not all places ask that you use a file sharing solution - google drive, 
box etc for large files.

--srs

From: mailop  on behalf of Adam Moffett via mailop 

Sent: Friday, October 23, 2020 11:17:00 PM
To: mailop@mailop.org 
Subject: Re: [mailop] Maximum message size

Yes, it was set to 200MB years ago by request of an engineer sending CAD files.
Now I have someone else who wants it larger.

Meanwhile I have found in Google searching that GMail allows 25MB and I believe 
O365 is 150MB max.

My initial impulse was to say no to this request because I'm aware of the DOS 
possibilities with large email sizes, but I thought I'd ask the community to 
see if I'm behind the times on what we think is too large.



-- Original Message --
From: "Suresh Ramasubramanian" mailto:ops.li...@gmail.com>>
To: "Adam Moffett" mailto:a...@plexicomm.net>>; 
"mailop@mailop.org<mailto:mailop@mailop.org>" 
mailto:mailop@mailop.org>>
Sent: 10/23/2020 1:39:06 PM
Subject: Re: [mailop] Maximum message size

How many providers are going to accept 200 mb emails if you enable this and 
someone then tries to send one out?

--srs

From: mailop mailto:mailop-boun...@mailop.org>> on 
behalf of Adam Moffett via mailop mailto:mailop@mailop.org>>
Sent: Friday, October 23, 2020 10:53:51 PM
To: mailop@mailop.org<mailto:mailop@mailop.org> 
mailto:mailop@mailop.org>>
Subject: [mailop] Maximum message size

I'm at 200MB maximum message size and have someone requesting we increase that 
limit.

Is there any current consensus on what it should be?


-- Adam Moffett, Network Engineer
Plexicomm - Internet Solutions | www.plexicomm.net
Office: 1.866.759.4678 x104

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Re: [mailop] Maximum message size

[Thomas Walter via mailop]

On 23.10.20 22:51, Jay Hennigan via mailop wrote:
> Perhaps someone should come up with a protocol designed to transfer
> files. They could name it File Transfer Protocol and abbreviate it FTP.

I'd prefer something with "Secure" in it's name though, preferably in
the front, so it shows the importance of it.

Regards,
Thomas Walter

-- 
Thomas Walter
Datenverarbeitungszentrale

FH Münster
- University of Applied Sciences -
Corrensstr. 25, Raum B 112
48149 Münster

Tel: +49 251 83 64 908
Fax: +49 251 83 64 910
www.fh-muenster.de/dvz/



smime.p7s
Description: S/MIME Cryptographic Signature
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Re: [mailop] Maximum message size

[Jaroslaw Rafa via mailop]

Dnia 23.10.2020 o godz. 17:47:00 Adam Moffett via mailop pisze:
> Yes, it was set to 200MB years ago by request of an engineer sending
> CAD files.
> Now I have someone else who wants it larger.

Does that someone know that services like WeTransfer or similar exist? Or
that one can share files via eg. Google Drive?
There are numerous possibilities instead of trying to send excessively large
files via email.
-- 
Regards,
   Jaroslaw Rafa
   r...@rafa.eu.org
--
"In a million years, when kids go to school, they're gonna know: once there
was a Hushpuppy, and she lived with her daddy in the Bathtub."
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Re: [mailop] Maximum message size

[Jay Hennigan via mailop]

On 10/23/20 10:23, Adam Moffett via mailop wrote:
I'm at 200MB maximum message size and have someone requesting we 
increase that limit.


Is there any current consensus on what it should be?


I think you'll find that the rest of the Internet has a limit far lower, 
about 20 MB is


Never underestimate the throughput of a FedEx truck full of hard drives. 
Or Dropbox, etc.


Perhaps someone should come up with a protocol designed to transfer 
files. They could name it File Transfer Protocol and abbreviate it FTP.


--
Jay Hennigan - j...@west.net
Network Engineering - CCIE #7880
503 897-8550 - WB6RDV
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Re: [mailop] Maximum message size

[Suresh Ramasubramanian via mailop]

Some of the largest emails I’m seeing over the years are random spams with huge 
amounts of hashbuster text, that figure out that many spam filters will skip 
scanning overly large emails.  Most regular users these days appear to know 
about and use file sharing services.

--srs

From: mailop  on behalf of Michael Peddemors via 
mailop 
Sent: Friday, October 23, 2020 11:38:53 PM
To: mailop@mailop.org 
Subject: Re: [mailop] Maximum message size

By default we still distribute with a 10MG maximum size, but frankly
almost all of our customers has bumped it to the maximum we recommend,
which is 20MG.  (the odd one even went to 30, but we don't recommend that)

Too bad this isnt' escalated to a recommended standard.

How about we use this as a chance to discuss this with other groups such
as M3AAWG and IETF, to try to come up with a written consensus for
others to follow.. (I think gmail still has the 25MG max size, but
someone can correct me on that)

On 2020-10-23 10:48 a.m., Evert Mouw via mailop wrote:
> On 10/23/20 7:23 PM, Adam Moffett via mailop wrote:
>> I'm at 200MB maximum message size and have someone requesting we
>> increase that limit.
>>
>> Is there any current consensus on what it should be?
>>
>
> Current default max. message size for Postfix configurations:
>
> message_size_limit (default: 1024) / The maximal size in bytes of a
> message, including envelope information.
>
> http://www.postfix.org/postconf.5.html
>
> Also Microsoft Exchange 2019 has a default limit of 10 MB.
>
> https://docs.microsoft.com/en-us/exchange/mail-flow/message-size-limits?view=exchserver-2019
>
> Increase the limit all you want but don't expect other parties to accept
> or deliver large messages. I would not increase, but DEcrease the limit
> in your case. Learn the user to use other file transfer methods, or if
> you like Thunderbird, check this:
>
> https://support.mozilla.org/en-US/kb/filelink-large-attachments
>
> Regards, Evert
>
>
>
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>



--
"Catch the Magic of Linux..."

Michael Peddemors, President/CEO LinuxMagic Inc.
Visit us at http://www.linuxmagic.com @linuxmagic
A Wizard IT Company - For More Info http://www.wizard.ca
"LinuxMagic" a Registered TradeMark of Wizard Tower TechnoServices Ltd.

604-682-0300 Beautiful British Columbia, Canada

This email and any electronic data contained are confidential and intended
solely for the use of the individual or entity to which they are addressed.
Please note that any views or opinions presented in this email are solely
those of the author and are not intended to represent those of the company.
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Re: [mailop] Maximum message size

[Robert Blayzor via mailop]

On 10/23/20 1:23 PM, Adam Moffett via mailop wrote:
> I'm at 200MB maximum message size and have someone requesting we
> increase that limit.
> 
> Is there any current consensus on what it should be?


Sheesh...  Sounds like someone needs Dropbox or Nextcloud...

-- 
inoc.net!rblayzor
XMPP: rblayzor.AT.inoc.net
PGP:  https://pgp.inoc.net/rblayzor/
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Re: [mailop] Maximum message size

[Michael Peddemors via mailop]

By default we still distribute with a 10MG maximum size, but frankly 
almost all of our customers has bumped it to the maximum we recommend, 
which is 20MG.  (the odd one even went to 30, but we don't recommend that)


Too bad this isnt' escalated to a recommended standard.

How about we use this as a chance to discuss this with other groups such 
as M3AAWG and IETF, to try to come up with a written consensus for 
others to follow.. (I think gmail still has the 25MG max size, but 
someone can correct me on that)


On 2020-10-23 10:48 a.m., Evert Mouw via mailop wrote:

On 10/23/20 7:23 PM, Adam Moffett via mailop wrote:
I'm at 200MB maximum message size and have someone requesting we 
increase that limit.


Is there any current consensus on what it should be?



Current default max. message size for Postfix configurations:

message_size_limit (default: 1024) / The maximal size in bytes of a 
message, including envelope information.


http://www.postfix.org/postconf.5.html

Also Microsoft Exchange 2019 has a default limit of 10 MB.

https://docs.microsoft.com/en-us/exchange/mail-flow/message-size-limits?view=exchserver-2019

Increase the limit all you want but don't expect other parties to accept 
or deliver large messages. I would not increase, but DEcrease the limit 
in your case. Learn the user to use other file transfer methods, or if 
you like Thunderbird, check this:


https://support.mozilla.org/en-US/kb/filelink-large-attachments

Regards, Evert



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--
"Catch the Magic of Linux..."

Michael Peddemors, President/CEO LinuxMagic Inc.
Visit us at http://www.linuxmagic.com @linuxmagic
A Wizard IT Company - For More Info http://www.wizard.ca
"LinuxMagic" a Registered TradeMark of Wizard Tower TechnoServices Ltd.

604-682-0300 Beautiful British Columbia, Canada

This email and any electronic data contained are confidential and intended
solely for the use of the individual or entity to which they are addressed.
Please note that any views or opinions presented in this email are solely
those of the author and are not intended to represent those of the company.
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Re: [mailop] Maximum message size

[Evert Mouw via mailop]

On 10/23/20 7:23 PM, Adam Moffett via mailop wrote:
I'm at 200MB maximum message size and have someone requesting we 
increase that limit.


Is there any current consensus on what it should be?



Current default max. message size for Postfix configurations:

message_size_limit (default: 1024) / The maximal size in bytes of a 
message, including envelope information.


http://www.postfix.org/postconf.5.html

Also Microsoft Exchange 2019 has a default limit of 10 MB.

https://docs.microsoft.com/en-us/exchange/mail-flow/message-size-limits?view=exchserver-2019

Increase the limit all you want but don't expect other parties to accept 
or deliver large messages. I would not increase, but DEcrease the limit 
in your case. Learn the user to use other file transfer methods, or if 
you like Thunderbird, check this:


https://support.mozilla.org/en-US/kb/filelink-large-attachments

Regards, Evert


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Re: [mailop] Maximum message size

[Eric Tykwinski via mailop]

Exactly what I was thinking:

150MB for Microsoft Online
https://docs.microsoft.com/en-us/office365/servicedescriptions/exchange-onli
ne-service-description/exchange-online-limits#message-limits-1

50 MB for GSuite: https://support.google.com/a/answer/175121?hl=en

 

If you can upsell to something like NextCloud/GDrive/OneDrive et al..

 

Sincerely,

 

Eric Tykwinski

TrueNet, Inc.

P: 610-429-8300

 

From: mailop  On Behalf Of Suresh Ramasubramanian
via mailop
Sent: Friday, October 23, 2020 1:39 PM
To: Adam Moffett ; mailop@mailop.org
Subject: Re: [mailop] Maximum message size

 

How many providers are going to accept 200 mb emails if you enable this and
someone then tries to send one out?

 

--srs

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Re: [mailop] Maximum message size

[Adam Moffett via mailop]

Yes, it was set to 200MB years ago by request of an engineer sending CAD 
files.

Now I have someone else who wants it larger.

Meanwhile I have found in Google searching that GMail allows 25MB and I 
believe O365 is 150MB max.


My initial impulse was to say no to this request because I'm aware of 
the DOS possibilities with large email sizes, but I thought I'd ask the 
community to see if I'm behind the times on what we think is too large.




-- Original Message --
From: "Suresh Ramasubramanian" 
To: "Adam Moffett" ; "mailop@mailop.org" 


Sent: 10/23/2020 1:39:06 PM
Subject: Re: [mailop] Maximum message size

How many providers are going to accept 200 mb emails if you enable this 
and someone then tries to send one out?


--srs

From: mailop  on behalf of Adam Moffett via 
mailop 

Sent: Friday, October 23, 2020 10:53:51 PM
To:mailop@mailop.org 
Subject: [mailop] Maximum message size

I'm at 200MB maximum message size and have someone requesting we 
increase that limit.


Is there any current consensus on what it should be?


-- Adam Moffett, Network Engineer
Plexicomm - Internet Solutions | www.plexicomm.net
Office: 1.866.759.4678 x104
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Re: [mailop] Maximum message size

[Suresh Ramasubramanian via mailop]

How many providers are going to accept 200 mb emails if you enable this and 
someone then tries to send one out?

--srs

From: mailop  on behalf of Adam Moffett via mailop 

Sent: Friday, October 23, 2020 10:53:51 PM
To: mailop@mailop.org 
Subject: [mailop] Maximum message size

I'm at 200MB maximum message size and have someone requesting we increase that 
limit.

Is there any current consensus on what it should be?


-- Adam Moffett, Network Engineer
Plexicomm - Internet Solutions | www.plexicomm.net
Office: 1.866.759.4678 x104

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[mailop] Maximum message size

[Adam Moffett via mailop]

I'm at 200MB maximum message size and have someone requesting we 
increase that limit.


Is there any current consensus on what it should be?


-- Adam Moffett, Network Engineer
Plexicomm - Internet Solutions | www.plexicomm.net
Office: 1.866.759.4678 x104
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