Re: [mailop] Best strategy to prune address list
On 11/23/19 13:06, Rolf E. Sonneveld via mailop wrote: Do you have some examples of reputable list cleaning services? Devlin Null does a very thorough job of removing questionable addresses. If you're considering mass email to a list of unknown or sketchy provenance, feed it to Dev. -- Jay Hennigan - j...@west.net Network Engineering - CCIE #7880 503 897-8550 - WB6RDV ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
Dnia 24.11.2019 o godz. 22:20:15 Michael Orlitzky via mailop pisze: > On 11/24/19 12:17 PM, Jaroslaw Rafa via mailop wrote: > > > > Just to be precise, you should check for either MX or A/ record. > > This prevents you from eliminating a huge number of bad addresses, > though, to save a negligible amount of good ones. I don't agree that it's a "negligible amount". The most common case when you don't need (and usually don't use) a MX record is a small site with just one server used for web, email & everything else. Then you just define an A record for "some.domain.net" and you're done. Having a MX record is completely superfluous in this case, as it would be something like "some.domain.net MX 10 some.domain.net" which is - basically - repeating the same thing twice. There isn't and never was a requirement that you *must* have a MX record to receive mail. -- 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." ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On Sun, Nov 24, 2019, Michael Orlitzky via mailop wrote: > For the same reason, I would recommend verifying the addresses against a > simple regular expression to catch typos, rather than against the full > rfc5322 grammar which allows basically anything. Hopefully not the one which is used on most websites that excludes the use of + in localpart :-) ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On 11/24/19 12:17 PM, Jaroslaw Rafa via mailop wrote: > > Just to be precise, you should check for either MX or A/ record. This prevents you from eliminating a huge number of bad addresses, though, to save a negligible amount of good ones. For the same reason, I would recommend verifying the addresses against a simple regular expression to catch typos, rather than against the full rfc5322 grammar which allows basically anything. ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
Dnia 24.11.2019 o godz. 17:47:43 hg user via mailop pisze: > When I had to do this kind of work on a mailing list, *more than 10 years > ago*, I started creating a list of all the unique email domains, then with > a script check if a MX record was present. Just to be precise, you should check for either MX or A/ record. If there is no MX record for the domain, but there is an A/ record, the mail could still be delivered to the host indicated by that record (if it happens to be a mail server). -- 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." ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
When I had to do this kind of work on a mailing list, *more than 10 years ago*, I started creating a list of all the unique email domains, then with a script check if a MX record was present. I think this method can be used today just to check how many domains are no longer active and how many addresses are from those domains… a high number may indicate that the list is really "broken"... ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
Dnia 23.11.2019 o godz. 20:05:07 Tom Ivar Helbekkmo via mailop pisze: > In the olden days, one would simply write a script, using expect(1) or > similar, to go through the addresses, connect to the target MTAs, and do > an SMTP VRFY on the recipient address. Today, I suspect that most MTAs > will refuse to service a VRFY request. SMTP VRFY was basically never widely adopted. There were always many mail servers that didn't accept VRFY. That's why MTAs that have "sender verification" feature on incoming mail do it by just trying to send mail back to the sender and checking the reply they get on RCPT command. If RCPT is accepted, they assume the e-mail address exists (and accept mail from that sender), if it is rejected, they reject the incoming mail too, assuming the sender doesn't exist. After that, they just send RSET, cancelling the send attempt. As someone already noted, there are also standalone tools that implement the same technique. However, I don't know what impact on reputation could have a large-scale use of this address verification method. -- 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." ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On Sat, Nov 23, 2019, Tom Ivar Helbekkmo via mailop wrote: > In the olden days, one would simply write a script, using expect(1) or > similar, to go through the addresses, connect to the target MTAs, and do > an SMTP VRFY on the recipient address. Today, I suspect that most MTAs Some MTAs have a "sender verification/callback" functionality (also available in "milters"), AFAICT they simply use "RCPT". There are most likely standalone versions/tools too (I have one). ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On 23 Nov 2019, at 16:06, Rolf E. Sonneveld via mailop wrote: Do you have some examples of reputable list cleaning services? No such entity can exist in the modern world. As Matt noted, without a reliable provenance and explicit permission for each and every address that might be subject to EU or CA law, mailing to a list is a legal risk. Any "list cleaner" who claims to be able to eliminate that risk is engaged in fraud (unless all they do is evaluating the list owner's existing provenance records.) -- Bill Cole b...@scconsult.com or billc...@apache.org (AKA @grumpybozo and many *@billmail.scconsult.com addresses) ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
There are also several legislative hurdles you’ll need to evaluate the list against. Two that come to mind are: Canada’s Anti-Spam Law has a two year expiry on implied consent. If you have addresses older than that in Canada you would likely be in violation of the law. GDPR also has some rules around understanding why a business is processing your data, why they have your data, how they use it, etc... all of this beyond consent. It’s rather complex for older data. if you don’t have the right consent and proof to back it up, track the source, and user location just cleaning the list won’t matter. ~ Matt > On Nov 23, 2019, at 16:15, Rolf E. Sonneveld via mailop > wrote: > > Hi, Steve, > >> On 23-11-19 20:18, Steve Atkins via mailop wrote: >> >>> On 23/11/2019 19:05, Tom Ivar Helbekkmo via mailop wrote: >>> "Rolf E. Sonneveld via mailop" writes: >>> What would be a good strategy for this customer to update his list of contacts? >> >> If it's old enough that they're asking the question, and are afraid of the >> impact of even a single "Hey, still interested?" email then toss the list >> and start over. Whatever process they go through to clean it up is going to >> leave it as still a junk list. >> >> If some of it is "old" (6+ months, say) then that applies to the old >> segment. Newer email addresses are likely recoverable. >> >> If there aren't any signup or last-mailed dates on the list then it's all >> old. > > To be honest, I don't know how old the list is, but thanks for your advise, > seems a good strategy to me. > >> >>> In the olden days, one would simply write a script, using expect(1) or >>> similar, to go through the addresses, connect to the target MTAs, and do >>> an SMTP VRFY on the recipient address. Today, I suspect that most MTAs >>> will refuse to service a VRFY request. >>> >>> Anyone know if that assumption is good? >> >> You're a couple of decades out of touch with email to even consider that >> approach. >> >> More usually a list owner who is really convinced they can save a bad list >> would buy list cleaning services from one of the companies that offer them. >> They'll use a variety of approaches to categorize the email addresses on a >> list into deliverable vs not. >> >> There are relatively reputable companies who offer email address validation >> or scoring, typically aiming at real-time validation at signup and similar >> situations. These are not the companies you go to for list cleaning. >> >> They're generally pretty inaccurate, and in ethics / respect for the email >> ecosystem only a step or two removed from professional spammers. If that. > > How can I distinguish one (list cleaning services) from the other (address > validation/scoring)? Do you have some examples of reputable list cleaning > services? > > Thanks, > /rolf > > > ___ > mailop mailing list > mailop@mailop.org > https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
Hi, Steve, On 23-11-19 20:18, Steve Atkins via mailop wrote: On 23/11/2019 19:05, Tom Ivar Helbekkmo via mailop wrote: "Rolf E. Sonneveld via mailop" writes: What would be a good strategy for this customer to update his list of contacts? If it's old enough that they're asking the question, and are afraid of the impact of even a single "Hey, still interested?" email then toss the list and start over. Whatever process they go through to clean it up is going to leave it as still a junk list. If some of it is "old" (6+ months, say) then that applies to the old segment. Newer email addresses are likely recoverable. If there aren't any signup or last-mailed dates on the list then it's all old. To be honest, I don't know how old the list is, but thanks for your advise, seems a good strategy to me. In the olden days, one would simply write a script, using expect(1) or similar, to go through the addresses, connect to the target MTAs, and do an SMTP VRFY on the recipient address. Today, I suspect that most MTAs will refuse to service a VRFY request. Anyone know if that assumption is good? You're a couple of decades out of touch with email to even consider that approach. More usually a list owner who is really convinced they can save a bad list would buy list cleaning services from one of the companies that offer them. They'll use a variety of approaches to categorize the email addresses on a list into deliverable vs not. There are relatively reputable companies who offer email address validation or scoring, typically aiming at real-time validation at signup and similar situations. These are not the companies you go to for list cleaning. They're generally pretty inaccurate, and in ethics / respect for the email ecosystem only a step or two removed from professional spammers. If that. How can I distinguish one (list cleaning services) from the other (address validation/scoring)? Do you have some examples of reputable list cleaning services? Thanks, /rolf ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On 2019-11-23 11:05 a.m., Tom Ivar Helbekkmo via mailop wrote: "Rolf E. Sonneveld via mailop" writes: What would be a good strategy for this customer to update his list of contacts? In the olden days, one would simply write a script, using expect(1) or similar, to go through the addresses, connect to the target MTAs, and do an SMTP VRFY on the recipient address. Today, I suspect that most MTAs will refuse to service a VRFY request. Anyone know if that assumption is good? -tih Unfortunately, yes.. 'all good intentions.. ' but because VRFY was quickly abused by list washers, and spammers doing dictionary attacks, and hackers testing data dumps from breaches.. VRFY is usually more strictly limited to in network tests, eg a firewall/gateway/appliance might use VRFY before sending messages through to an internal email server.. At least enough systems have stopped permitting it, to make it viable anymore. Not that turning it off stopped the distributed attacks.. -- "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. ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On 23 Nov 2019, at 11:05, Tom Ivar Helbekkmo via mailop wrote: > Today, I suspect that most MTAs > will refuse to service a VRFY request. > > Anyone know if that assumption is good? I would be very surprised if you were wrong. -lem ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On 23/11/2019 19:05, Tom Ivar Helbekkmo via mailop wrote: "Rolf E. Sonneveld via mailop" writes: What would be a good strategy for this customer to update his list of contacts? If it's old enough that they're asking the question, and are afraid of the impact of even a single "Hey, still interested?" email then toss the list and start over. Whatever process they go through to clean it up is going to leave it as still a junk list. If some of it is "old" (6+ months, say) then that applies to the old segment. Newer email addresses are likely recoverable. If there aren't any signup or last-mailed dates on the list then it's all old. In the olden days, one would simply write a script, using expect(1) or similar, to go through the addresses, connect to the target MTAs, and do an SMTP VRFY on the recipient address. Today, I suspect that most MTAs will refuse to service a VRFY request. Anyone know if that assumption is good? You're a couple of decades out of touch with email to even consider that approach. More usually a list owner who is really convinced they can save a bad list would buy list cleaning services from one of the companies that offer them. They'll use a variety of approaches to categorize the email addresses on a list into deliverable vs not. There are relatively reputable companies who offer email address validation or scoring, typically aiming at real-time validation at signup and similar situations. These are not the companies you go to for list cleaning. They're generally pretty inaccurate, and in ethics / respect for the email ecosystem only a step or two removed from professional spammers. If that. Cheers, Steve ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
"Rolf E. Sonneveld via mailop" writes: > What would be a good strategy for this customer to update his list of > contacts? In the olden days, one would simply write a script, using expect(1) or similar, to go through the addresses, connect to the target MTAs, and do an SMTP VRFY on the recipient address. Today, I suspect that most MTAs will refuse to service a VRFY request. Anyone know if that assumption is good? -tih -- Most people who graduate with CS degrees don't understand the significance of Lisp. Lisp is the most important idea in computer science. --Alan Kay ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
Re: [mailop] Best strategy to prune address list
On 11/23/19 02:57, Rolf E. Sonneveld via mailop wrote: Hi, over the years, one of my customers has built up a list of contacts (mail addresses). He didn't use the list for quite some time and now he > wants to prune the list by checking the existence/validity of the addresses and remove the addresses that no longer exists. Simply sending a verification mail to 100,000 addresses will have negative impact on the reputation of his domain/addresses/egress mail servers, wouldn't it? What would be a good strategy for this customer to update his list of contacts? * What is "quite some time"? Six months? A year? Ten years? * How were the addresses obtained? Confirmed opt-in? * Does the customer intend to use the list for marketing? * Is there other interaction (transactional, one-on-one) with any of the addresses on the list? If "quite some time" is several years and there has been zero other interaction with the list, it's probably best to start over by mailing to those with which the customer has had recent interaction. -- Jay Hennigan - j...@west.net Network Engineering - CCIE #7880 503 897-8550 - WB6RDV ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
[mailop] Best strategy to prune address list
Hi, over the years, one of my customers has built up a list of contacts (mail addresses). He didn't use the list for quite some time and now he wants to prune the list by checking the existence/validity of the addresses and remove the addresses that no longer exists. Simply sending a verification mail to 100,000 addresses will have negative impact on the reputation of his domain/addresses/egress mail servers, wouldn't it? What would be a good strategy for this customer to update his list of contacts? Thanks, /rolf ___ mailop mailing list mailop@mailop.org https://chilli.nosignal.org/cgi-bin/mailman/listinfo/mailop
