Re: [Dovecot] Size of Mailbox affecting the sending of mail?
On 24.8.2012, at 13.53, Tim Smith wrote: Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a brief discussion with someone, they mentioned that the reason that this may be to do with the size of the mailbox. I couldn't see the rationale behind this unless Dovecot is syncing the mailbox after every sent mail (due to possibly saving the sent item?) The mail is being delivered successfully but the amount of time it is taking to complete the action is far too long! Other than the bandwidth others already mentioned, the only reason it could be Dovecot's fault is exactly the size of the Sent mailbox. How large is that and what mailbox format are you using?
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
On 8/24/2012 8:49 AM, Tim Smith wrote: My next guess was the upstream data rate. My router states that the upstream is 10x slower than downstream so I guess this is the culprit. Time to move to a VPS methinks... Ok, you stated that you have multiple user PCs that are slow when sending. I guess, asked, if they were all behind the same DSL/Cable line and if the Dovecot server was local or remote. If the user PCs are local, and the server is remote, and the slow outbound speed of your internet connection is the cause of the slow sending, then I fail to see how moving to a VPS will help you. You're not providing sufficient technical details explaining what machines are located where. We need to know that to give you the correct answer(s) to your problem. -- Stan
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
Am 24.08.2012 12:53, schrieb Tim Smith: Hi, I didn't know where to post this one so I'll start off with you guys and then try Postfix if I'm barking up the wrong tree! Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a brief discussion with someone, they mentioned that the reason that this may be to do with the size of the mailbox. I couldn't see the rationale behind this unless Dovecot is syncing the mailbox after every sent mail (due to possibly saving the sent item?) The mail is being delivered successfully but the amount of time it is taking to complete the action is far too long! Sorry this is a bit vague but any advice on trying to diagnose the problem would be appreciated. Thanks in advance! Tim sending mail ist usual smtp ( postfix ), not dovecot if no firewalls/proxies , slow lines , dns problems are involved, there may exist some policy or milter service which slows down smtp out from i.e tb, ask same question with logs and config in the postfix mail list size of mailbox should be not involved in this -- Best Regards MfG Robert Schetterer
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
Thanks Robert. That's what I thought. I couldn't make the connection. Will try the Postfix list! On 24/08/12 12:06, Robert Schetterer wrote: Am 24.08.2012 12:53, schrieb Tim Smith: Hi, I didn't know where to post this one so I'll start off with you guys and then try Postfix if I'm barking up the wrong tree! Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a brief discussion with someone, they mentioned that the reason that this may be to do with the size of the mailbox. I couldn't see the rationale behind this unless Dovecot is syncing the mailbox after every sent mail (due to possibly saving the sent item?) The mail is being delivered successfully but the amount of time it is taking to complete the action is far too long! Sorry this is a bit vague but any advice on trying to diagnose the problem would be appreciated. Thanks in advance! Tim sending mail ist usual smtp ( postfix ), not dovecot if no firewalls/proxies , slow lines , dns problems are involved, there may exist some policy or milter service which slows down smtp out from i.e tb, ask same question with logs and config in the postfix mail list size of mailbox should be not involved in this
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
Hi all, Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a While in the first place sending e-mail has to do with SMTP and not IMAP, most mail client programs are configured to save a copy of an e-mail using FCC (file carbon copy) by putting this copy via IMAP into some Sent folder. And here you are: this may explain the long delays, esp. if on some asymmetric connection like DSL with low upstream bandwith. Just my 2c Cheers and have a nice weekend -- Dirk Jahnke-Zumbusch Deutsches Elektronen-Synchrotron DESY
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
Am 24.08.2012 13:35, schrieb Jahnke-Zumbusch, Dirk: Hi all, Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a While in the first place sending e-mail has to do with SMTP and not IMAP, most mail client programs are configured to save a copy of an e-mail using FCC (file carbon copy) by putting this copy via IMAP into some Sent folder. And here you are: this may explain the long delays, esp. if on some asymmetric connection like DSL with low upstream bandwith. Just my 2c Cheers and have a nice weekend -- Dirk Jahnke-Zumbusch Deutsches Elektronen-Synchrotron DESY very true, but tb should show the copy action, unless its not configured not to do so -- Best Regards MfG Robert Schetterer
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
On 8/24/2012 5:53 AM, Tim Smith wrote: Hay Tim, Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a brief discussion with someone, they mentioned that the reason that this may be to do with the size of the mailbox. I couldn't see the rationale behind this unless Dovecot is syncing the mailbox after every sent mail (due to possibly saving the sent item?) The mail is being delivered successfully but the amount of time it is taking to complete the action is far too long! You probably have multiple factors involved in this mail sending delay issue. One may be that you're not bypassing your Postfix restrictions on your submission service. To fix this, disable your restrictions in the master.cf service definition of your submission service. For example: 587 inet n - n - - smtpd -o smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes -o content_filter= -o smtpd_client_restrictions= -o smtpd_helo_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,\ permit_sasl_authenticated,reject -o receive_override_options=no_unknown_recipient_checks,\ no_address_mappings,no_header_body_checks This should squash any/all delays in Postfix submission. Another is the fact you're storing the users' Sent folders on the IMAP server. Typically there's nothing wrong with this. I do this and I see zero delay in Tbird. If a good portion of the delay you're seeing is Tbird copying messages to the Sent folder then I'd say you may have a duplex mismatch or some other network layer issue. What is the network topology between these client MUAs and the server? Full duplex fast ethernet? GbE? Or is the server at a remote location, say a colo/VPS server, and your clients are submitting over a shared ADSL/cable circuit to the server? If this is the case you'll always have substantial delays as the real outbound transmission rate of the best ADSL/cable circuits is only 500-1000 Kbps. Sending an attachment over such a pipe is always going to be slow, doubly so if you're copying to an IMAP Sent folder over the same connection, plus sharing it for web browsing, etc, amongst many users. If this is a SOHO environment with shared ADSL/cable the server needs to be on site, with clients connected via ethernet. This will allow instantaneous submission and Sent copying, while pushing the delay to the Postfix outbound queue, where it's invisible to your users. -- Stan
Re: [Dovecot] Size of Mailbox affecting the sending of mail?
My next guess was the upstream data rate. My router states that the upstream is 10x slower than downstream so I guess this is the culprit. Time to move to a VPS methinks... On 24/08/12 13:50, Stan Hoeppner wrote: On 8/24/2012 5:53 AM, Tim Smith wrote: Hay Tim, Having set up my mail server (Dovecot/Postfix), users are experiencing long delays (a couple of minutes) when sending mail from mail client such as Thunderbird - this increases with attachments. Having had a brief discussion with someone, they mentioned that the reason that this may be to do with the size of the mailbox. I couldn't see the rationale behind this unless Dovecot is syncing the mailbox after every sent mail (due to possibly saving the sent item?) The mail is being delivered successfully but the amount of time it is taking to complete the action is far too long! You probably have multiple factors involved in this mail sending delay issue. One may be that you're not bypassing your Postfix restrictions on your submission service. To fix this, disable your restrictions in the master.cf service definition of your submission service. For example: 587 inet n - n - - smtpd -o smtpd_enforce_tls=yes -o smtpd_sasl_auth_enable=yes -o content_filter= -o smtpd_client_restrictions= -o smtpd_helo_restrictions= -o smtpd_sender_restrictions= -o smtpd_recipient_restrictions=permit_mynetworks,\ permit_sasl_authenticated,reject -o receive_override_options=no_unknown_recipient_checks,\ no_address_mappings,no_header_body_checks This should squash any/all delays in Postfix submission. Another is the fact you're storing the users' Sent folders on the IMAP server. Typically there's nothing wrong with this. I do this and I see zero delay in Tbird. If a good portion of the delay you're seeing is Tbird copying messages to the Sent folder then I'd say you may have a duplex mismatch or some other network layer issue. What is the network topology between these client MUAs and the server? Full duplex fast ethernet? GbE? Or is the server at a remote location, say a colo/VPS server, and your clients are submitting over a shared ADSL/cable circuit to the server? If this is the case you'll always have substantial delays as the real outbound transmission rate of the best ADSL/cable circuits is only 500-1000 Kbps. Sending an attachment over such a pipe is always going to be slow, doubly so if you're copying to an IMAP Sent folder over the same connection, plus sharing it for web browsing, etc, amongst many users. If this is a SOHO environment with shared ADSL/cable the server needs to be on site, with clients connected via ethernet. This will allow instantaneous submission and Sent copying, while pushing the delay to the Postfix outbound queue, where it's invisible to your users.
