IMAP connection lost while sending mail
Hello,
we have a strange problem.
Costumer use Outlook to connect to our IMAP and SMTP Server. While sending Mails Outlooks reports connection lost. In Mail log there is no reason logged or something else.
What i dont understand is that IMAP lose connetion while using SMTP. Outlloks reports problem by moving mails into Send dir.
Is that a Outlook problem?
i have enables debug logging and cant see any reason :(
Network was already testet.
any ideas?
Kind regards Philipp
-- Philipp Ewald Administrator
DigiOnline GmbH, Probsteigasse 15 - 19, 50670 Köln Fax: +49 221 6500-690, E-Mail: philipp.ewald@digionline.de
AG Köln HRB 27711, St.-Nr. 5215 5811 0640 Geschäftsführer: Werner Grafenhain
Informationen zum Datenschutz: www.digionline.de/ds
What version of outlook is your customer using?
and what internet provider (cell, dsl, cable, fiber etc) ?
anything past 2010 can be a crap shoot at best.
I have had many many customers try to use outlook because it is fancier interface wise but outlook just does not really support imap properly.
Last time i googled this it cam back with over 2 millions hits on outlook imap issues. All suggestions fell back to connect using exchange protocol's there was no real answer.
I have been testing myself with 2019 office and it seems to work kinda.
On another major note with outlook it can only handle up to maybe 1000 emails per folder or it will constantly sync and spend more time doing that then anything else.
Outlook also does NOT support idle. (again echange thingy)
I find thunderbird works best (even though they have issues to sort out as well here and there)
I run thunderbird and can comfortably run up to 10000 emails in a folder.
It's a microsoft thing pushing exchange / outlook 365 against imap.
This is NO Fault of Dovecot / Cyrus or any other imap server.
Best suggestions for outlook look is to use
Port 143 for imap (you can use ssl on port 143)
Port 587 for smtp (25 is sometimes blocked by your isp) - Note on smtp connections there are some isp's blocking normal ports, i had to open up 10000 on my postfix to get around at&t blocking smtp sends from a tethered cell phone connection for one of my customers which fixed the issue.
Also outlook timeouts for both send and receive should be pushed up to a couple of minutes to cover any timing issues (although 30 seconds should be ok in most cases i have found outlook to fail with unknown reasons).
One more thing about outlook is to speed up the user interface in some cases they will give you an option on the bottom of the inbox to load more messages, this should be checked as i have had several customers forget about old emails and the inbox could just simply be going past 1000 messages without any kind of warning. (see above)
Hope this helps
Happy Friday !!! Thanks - paul
Paul Kudla
Scom.ca Internet Services http://www.scom.ca 004-1009 Byron Street South Whitby, Ontario - Canada L1N 4S3
Toronto 416.642.7266 Main 1.866.411.7266 Fax 1.888.892.7266
On 5/6/2022 3:53 AM, Philipp Ewald wrote:
Hello,
we have a strange problem.
Costumer use Outlook to connect to our IMAP and SMTP Server. While sending Mails Outlooks reports connection lost. In Mail log there is no reason logged or something else.
What i dont understand is that IMAP lose connetion while using SMTP. Outlloks reports problem by moving mails into Send dir.
Is that a Outlook problem?
i have enables debug logging and cant see any reason :(
Network was already testet.
any ideas?
Kind regards Philipp
Hello Paul and Kevin,
thanks for your replys!
Problem is, i am Administrator from mail Server and customer has there own administrator. Me and the other IT don't know whats the problem is.
I will tell them too do some more testing and maybe switching Mailclient, Outlooks is horrible... I will try other Ports and ask if there can clean up the mailbox (PC was already cleaned and still not work)
On time i was there and i had no problem with my Linux + Thunderbird... so network is working.
1 - Time it. Is it hitting a specific time and giving up? It looks like there is instant problem, Outlook reporting problem Moving Mail into "Sent"
2 - Does the email have any specific content? its random problem, mostly this error happen when there are some more recipient, but sometime problem with less recipient.
3 - Do they have anything like A/V software that might be acting to try and proxy / scan the email? there told me there has tested on a new installed windows with out any "rules/extra software" applied on
Thanks i will report if we had some success.
Have a nice weekend!
Am 06.05.22 um 12:55 schrieb Paul Kudla (SCOM.CA Internet Services Inc.):
What version of outlook is your customer using?
and what internet provider (cell, dsl, cable, fiber etc) ?
anything past 2010 can be a crap shoot at best.
I have had many many customers try to use outlook because it is fancier interface wise but outlook just does not really support imap properly.
Last time i googled this it cam back with over 2 millions hits on outlook imap issues. All suggestions fell back to connect using exchange protocol's there was no real answer.
I have been testing myself with 2019 office and it seems to work kinda.
On another major note with outlook it can only handle up to maybe 1000 emails per folder or it will constantly sync and spend more time doing that then anything else.
Outlook also does NOT support idle. (again echange thingy)
I find thunderbird works best (even though they have issues to sort out as well here and there)
I run thunderbird and can comfortably run up to 10000 emails in a folder.
It's a microsoft thing pushing exchange / outlook 365 against imap.
This is NO Fault of Dovecot / Cyrus or any other imap server.
Best suggestions for outlook look is to use
Port 143 for imap (you can use ssl on port 143)
Port 587 for smtp (25 is sometimes blocked by your isp) - Note on smtp connections there are some isp's blocking normal ports, i had to open up 10000 on my postfix to get around at&t blocking smtp sends from a tethered cell phone connection for one of my customers which fixed the issue.
Also outlook timeouts for both send and receive should be pushed up to a couple of minutes to cover any timing issues (although 30 seconds should be ok in most cases i have found outlook to fail with unknown reasons).
One more thing about outlook is to speed up the user interface in some cases they will give you an option on the bottom of the inbox to load more messages, this should be checked as i have had several customers forget about old emails and the inbox could just simply be going past 1000 messages without any kind of warning. (see above)
Hope this helps
Happy Friday !!! Thanks - paul
Paul Kudla
Scom.ca Internet Services http://www.scom.ca 004-1009 Byron Street South Whitby, Ontario - Canada L1N 4S3
Toronto 416.642.7266 Main 1.866.411.7266 Fax 1.888.892.7266
On 5/6/2022 3:53 AM, Philipp Ewald wrote:
Hello,
we have a strange problem.
Costumer use Outlook to connect to our IMAP and SMTP Server. While sending Mails Outlooks reports connection lost. In Mail log there is no reason logged or something else.
What i dont understand is that IMAP lose connetion while using SMTP. Outlloks reports problem by moving mails into Send dir.
Is that a Outlook problem?
i have enables debug logging and cant see any reason :(
Network was already testet.
any ideas?
Kind regards Philipp
-- Philipp Ewald Administrator
DigiOnline GmbH, Probsteigasse 15 - 19, 50670 Köln Fax: +49 221 6500-690, E-Mail: philipp.ewald@digionline.de
AG Köln HRB 27711, St.-Nr. 5215 5811 0640 Geschäftsführer: Werner Grafenhain
Informationen zum Datenschutz: www.digionline.de/ds
OK this is starting to make more sense
Time it. Is it hitting a specific time and giving up?
It looks like there is instant problem, Outlook reporting problem Moving Mail into "Sent"
<<<
Note one more issue with using Outlook past 2012
YOU MUST GOTO the control panel (old one in win 10) and use the Mail Setup - Outlook (32bit)
Outlook itself seems to block any real access to the advanced settings.
That being Said ....
Ok Outlook imap may have the sent folder destination setup wrong?
first off with dovecot use the default Folder
(Root folder path option box == Blank)
Next thing to check (and microsoft moved this around)
Is the destination imap folder top place a sent copy in
2019 seems to be here ?
Home (in top bar) then Rules (aprox 2/3's over)
apparently you need to create a rule to change the destination folder?
previous outlook versions have a place a copy in this folder option (fyi) in the advanced setup via the control panel.
In general imap returns all the special folders when logging into the server
The issue with outlook and outlook 365 is they tend to make a Sent folder (for example) in the root path of the imap account
or
something under the INBOX (Like INBOX/Sent)
at the end of the day if you have access to the Dovecot Server check the mail dir structure
verify where the sent folder is
below is from an old cyrus import (to give an example of what might be happening) you will notice that there is NO .Sent folder but a INBOX.Sent folder
drwx------ 5 vmail vmail uarch 8B May 6 05:10 .INBOX.Drafts drwx------ 5 vmail vmail uarch 9B May 6 05:10 .INBOX.Sent drwx------ 5 vmail vmail uarch 8B May 6 05:10 .INBOX.Trash -rw------- 1 vmail vmail uarch 571B May 3 15:18 .dovecot.lda-dupes drwx------ 5 vmail vmail uarch 9B May 6 05:10 .dovecot.lda-dupes.locks drwx------ 2 vmail vmail uarch 2B Apr 2 13:11 cur -rw------- 1 vmail vmail uarch 5.6K May 5 13:29 dovecot-uidlist -rw------- 1 vmail vmail uarch 8B May 1 13:05 dovecot-uidvalidity -r--r--r-- 1 vmail vmail uarch 0B Feb 20 07:16 dovecot-uidvalidity.6212313e -rw------- 1 vmail vmail uarch 2.5K May 5 13:29 dovecot.index -rw------- 1 vmail vmail uarch 28K May 6 05:10 dovecot.index.cache -rw------- 1 vmail vmail uarch 568B May 6 05:10 dovecot.index.log -rw------- 1 vmail vmail uarch 32K May 5 13:29 dovecot.index.log.2 -rw------- 1 vmail vmail uarch 1.3K May 3 05:10 dovecot.list.index -rw------- 1 vmail vmail uarch 7.2K May 6 05:10 dovecot.list.index.log -rw------- 1 vmail vmail uarch 168B Feb 20 08:03 dovecot.mailbox.log drwx------ 2 vmail vmail uarch 95B May 5 13:29 new drwx------ 4 vmail vmail uarch 7B May 5 13:29 sieve -rw------- 1 vmail vmail uarch 77B Feb 20 08:03 subscriptions drwx------ 2 vmail vmail uarch 2B May 5 13:29 tmp
<<<
Below is a Normal Dovecot Struxture (from my experience)
drwx------ 28 vmail vmail uarch 42B May 6 10:16 . drwx------ 4 vmail vmail uarch 4B Feb 19 17:58 .. drwx------ 5 vmail vmail uarch 10B May 6 06:21 .Drafts drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2010 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2011 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2012 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2013 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2014 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2015 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2016 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2017 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2018 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2019 drwx------ 5 vmail vmail uarch 11B May 6 06:21 .INBOX.Archives.2020 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.2021 drwx------ 5 vmail vmail uarch 10B May 6 06:21 .INBOX.Archives.2022 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Archives.Sent 2022 drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Junk drwx------ 5 vmail vmail uarch 9B May 6 06:21 .INBOX.Notes drwx------ 5 vmail vmail uarch 10B May 6 06:21 .INBOX.Trash drwx------ 5 vmail vmail uarch 12B May 6 08:41 .Sent drwx------ 5 vmail vmail uarch 11B May 6 08:40 .Trash -rw------- 1 vmail vmail uarch 51B May 6 06:35 .dovecot.lda-dupes drwx------ 5 vmail vmail uarch 9B May 6 06:35 .dovecot.lda-dupes.locks drwx------ 2 vmail vmail uarch 1.8K May 6 09:08 cur -rw------- 1 vmail vmail uarch 52B Apr 26 08:03 dovecot-keywords -rw------- 1 vmail vmail uarch 131K May 6 09:08 dovecot-uidlist -rw------- 1 vmail vmail uarch 8B May 2 10:25 dovecot-uidvalidity -r--r--r-- 1 vmail vmail uarch 0B Feb 19 17:58 dovecot-uidvalidity.62117625 -rw------- 1 vmail vmail uarch 45K May 6 08:41 dovecot.index -rw------- 1 vmail vmail uarch 1.8M May 6 10:16 dovecot.index.cache -rw------- 1 vmail vmail uarch 26K May 6 09:09 dovecot.index.log -rw------- 1 vmail vmail uarch 32K May 4 10:56 dovecot.index.log.2 -rw------- 1 vmail vmail uarch 2.7K May 6 06:21 dovecot.list.index -rw------- 1 vmail vmail uarch 5.0K May 6 09:08 dovecot.list.index.log -rw------- 1 vmail vmail uarch 2.2K May 2 10:25 dovecot.mailbox.log -rw------- 1 vmail vmail uarch 0B Feb 19 17:58 maildirfolder drwx------ 2 vmail vmail uarch 2B May 6 09:08 new drwx------ 4 vmail vmail uarch 4B Feb 27 16:44 sieve -rw------- 1 vmail vmail uarch 364B May 2 10:25 subscriptions drwx------ 2 vmail vmail uarch 2B May 6 09:08 tmp
<<<
Notice the .Sent, .Trash folders are in the root.
this is what dovecot is probably returning in the login imap parameters
However if you are using INBOX/Sent then outlook is probably getting confusing thus causing the error ie the box would not be accessable.
another note do you have the auto creation turned on for the imap folders ?
namespace inbox { inbox = yes location = mailbox Drafts { auto = subscribe special_use = \Drafts } mailbox Sent { auto = subscribe special_use = \Sent } mailbox Trash { auto = subscribe special_use = \Trash } prefix = separator = / }
If not then outlook would be able to autocreate the Special Folders
I found that when migrating from cyrus imap i ended up with 2 sets of special folders which athough a mess was explanable because of what i am mentioning here.
if you turn on the auto create and restart dovecot chances are this might deal with your Special Folders as they will be re-created as per what / how outlook want to access them. (hopefully)
Another note is the subscriptions file in the maildir
# cat subscriptions V 2
INBOX Drafts Sent INBOX Archives 2010 INBOX Archives 2011 INBOX Archives INBOX Archives 2012 INBOX Archives 2013 INBOX Archives 2014 INBOX Archives 2015 INBOX Archives 2016 INBOX Archives 2017 INBOX Archives 2018 INBOX Archives 2019 INBOX Archives 2020 INBOX Archives 2021 INBOX Junk INBOX Notes Trash INBOX Archives 2022 INBOX Archives Sent 2022 INBOX Trash
this file sets the imap folder list and dir structure.
I found i had to manually fix some of these entries when moving from cyrus to dovecot
this file is the folder list that is sent to the IMAP email client and some times will not update correctly. (thunderbird as an example a lot of greyed out inaccessable folders were in this file and had to be removed)
Happy Hunting ....
Happy Friday !!! Thanks - paul
Paul Kudla
Scom.ca Internet Services http://www.scom.ca 004-1009 Byron Street South Whitby, Ontario - Canada L1N 4S3
Toronto 416.642.7266 Main 1.866.411.7266 Fax 1.888.892.7266
On 5/6/2022 10:30 AM, Philipp Ewald wrote:
Hello Paul and Kevin,
thanks for your replys!
Problem is, i am Administrator from mail Server and customer has there own administrator. Me and the other IT don't know whats the problem is.
I will tell them too do some more testing and maybe switching Mailclient, Outlooks is horrible... I will try other Ports and ask if there can clean up the mailbox (PC was already cleaned and still not work)
On time i was there and i had no problem with my Linux + Thunderbird... so network is working.
1 - Time it. Is it hitting a specific time and giving up? It looks like there is instant problem, Outlook reporting problem Moving Mail into "Sent"
2 - Does the email have any specific content? its random problem, mostly this error happen when there are some more recipient, but sometime problem with less recipient.
3 - Do they have anything like A/V software that might be acting to try and proxy / scan the email? there told me there has tested on a new installed windows with out any "rules/extra software" applied on
Thanks i will report if we had some success.
Have a nice weekend!
Am 06.05.22 um 12:55 schrieb Paul Kudla (SCOM.CA Internet Services Inc.):
What version of outlook is your customer using?
and what internet provider (cell, dsl, cable, fiber etc) ?
anything past 2010 can be a crap shoot at best.
I have had many many customers try to use outlook because it is fancier interface wise but outlook just does not really support imap properly.
Last time i googled this it cam back with over 2 millions hits on outlook imap issues. All suggestions fell back to connect using exchange protocol's there was no real answer.
I have been testing myself with 2019 office and it seems to work kinda.
On another major note with outlook it can only handle up to maybe 1000 emails per folder or it will constantly sync and spend more time doing that then anything else.
Outlook also does NOT support idle. (again echange thingy)
I find thunderbird works best (even though they have issues to sort out as well here and there)
I run thunderbird and can comfortably run up to 10000 emails in a folder.
It's a microsoft thing pushing exchange / outlook 365 against imap.
This is NO Fault of Dovecot / Cyrus or any other imap server.
Best suggestions for outlook look is to use
Port 143 for imap (you can use ssl on port 143)
Port 587 for smtp (25 is sometimes blocked by your isp) - Note on smtp connections there are some isp's blocking normal ports, i had to open up 10000 on my postfix to get around at&t blocking smtp sends from a tethered cell phone connection for one of my customers which fixed the issue.
Also outlook timeouts for both send and receive should be pushed up to a couple of minutes to cover any timing issues (although 30 seconds should be ok in most cases i have found outlook to fail with unknown reasons).
One more thing about outlook is to speed up the user interface in some cases they will give you an option on the bottom of the inbox to load more messages, this should be checked as i have had several customers forget about old emails and the inbox could just simply be going past 1000 messages without any kind of warning. (see above)
Hope this helps
Happy Friday !!! Thanks - paul
Paul Kudla
Scom.ca Internet Services http://www.scom.ca 004-1009 Byron Street South Whitby, Ontario - Canada L1N 4S3
Toronto 416.642.7266 Main 1.866.411.7266 Fax 1.888.892.7266
On 5/6/2022 3:53 AM, Philipp Ewald wrote:
Hello,
we have a strange problem.
Costumer use Outlook to connect to our IMAP and SMTP Server. While sending Mails Outlooks reports connection lost. In Mail log there is no reason logged or something else.
What i dont understand is that IMAP lose connetion while using SMTP. Outlloks reports problem by moving mails into Send dir.
Is that a Outlook problem?
i have enables debug logging and cant see any reason :(
Network was already testet.
any ideas?
Kind regards Philipp
On 5/6/2022 3:53 AM, Philipp Ewald wrote:
we have a strange problem.
Costumer use Outlook to connect to our IMAP and SMTP Server. While sending Mails Outlooks reports connection lost. In Mail log there is no reason logged or something else.
What i dont understand is that IMAP lose connetion while using SMTP. Outlloks reports problem by moving mails into Send dir.
Is that a Outlook problem?
i have enables debug logging and cant see any reason :(
Network was already testet.
Morning Philipp,
I would do a couple of things to troubleshoot:
1 - Time it. Is it hitting a specific time and giving up?
2 - Does the email have any specific content?
3 - Do they have anything like A/V software that might be acting to try and proxy / scan the email?
4 - Try putting thunderbird on the same machine for the same account with the same email. Does that work?
Regards,
KAM
participants (3)
-
Kevin A. McGrail
-
Paul Kudla (SCOM.CA Internet Services Inc.)
-
Philipp Ewald