Hi All,

This is my first post so forgive me if this hits the wrong list.

I have been using dovecot for years happily with SendMail on mainly CentOS servers, and my customers are starting to more and more use Thunderbird, so my perfect model is:

Linux --> Dovecot --> SendMail --> Thunderbird (or mobile phone e-mail app).

I do have some customers using Outlook or Windows Live Mail, and these are for the most part working fine with IMAP - I don't do POP.

My mod to the dovecot.conf file:

disable_plaintext_auth=no

My mod to conf.d/10-mail.conf:

#mail_location = mail_location = mbox:~/mail:INBOX=/var/spool/mail/%u

My mod to conf.d/10-master.conf:

#default_internal_user = dovecot

service imap-login { inet_listener imap { port = 143 } inet_listener imap_second { port = 10143 } inet_listener imaps { #port = 993 #ssl = yes }

• I do the 10143 bit so I can pseudo hide port 143 for clients with devices that access both internally and externally - port forwarded on MikroTik routers for my customers.

All goes well for many years with the above configs, and continues to be awesome as always.

Under the user's ${HOME} directory they end up with a lovely 'mail' directory and all of the e-mail client folders live in harmony under there.

This weekend I am helping a customer cut over his customer from legacy POP based e-mail uses with splatterings of Outlook 2010 and 2013 throughout the company, to using Linux with IMAP in the setup as described above as per my standard configs.

The issue starts when you add an IMAP user to the Outlook client and upon opening it, initially, it tries to find a "Sent" Items folder under IMAP to send from. To this end I have traditionally gone into the dialogue box that opens, click on the IMAP account to receive a list of possible folders, but it now immediately crashes indicating Outlook has had an error, and it all goes to hell from there. Outlook then cannot open but keeps crashing with its "unknown error". Up to last week at another site with Windows Live Mail, this was not an issue.

By modifying the e-mail account via Control Panel, I can delete or modify the account and try again.

Here is what I found:

If I don't specify a 'root' folder under the "Advanced" tab which also contains the port selections for 143 and 25, it fails.

If I follow the MS recommended root folder example from Microsoft and use INBOX, or Inbox, it 'does' stop the error but you can't create subfolders - I am assuming as this is picking up the .imap/INBOX folder or something and makes sense that it can't create folders under INBOX/Inbox, particularly if this is a file rather than a directory that dovecot/Outlook are pointing to.

What I have found is I can 'lie' to Outlook and put in a 'mail' folder. This results in a ${HOME}/login_name/mail/mail folder, but I don't care, as it happily puts files under mail/mail.

Now here is something totally strange: If I try to put this same account on another PC so users can 'share' the same e-mail account, even with my 'mail' root folder work-around, it crashes again.

All through this, Thuderbird works fine and so does RoundCube - SOGo will be up and working a bit later once I get the initial part up and going... but I digress but good to know it is only Outlook doing this.

To share multiple accounts I am currently getting the subsequent PCs that need to share a universal account to select a root folder mail2, mail3 etc. I then delete these folders and symbolic link the mail2, mail3 etc to the mail directory - yucky fix, but kind of works with some auto scripting of .subscriptions to follow so all of the Outlook clients sync to the one 'real' root folder.

I have never seen this before and have customers running all kinds of IMAP e-mail clients to dovecot on Linux.

I saw an MS posted bug on something for IMAP and they recommend rolling back MS updates to fix it - but I am not sure the client can or will do that.

This kind of random issue that only affects this site at present is why I only recommend people use e-mail clients like Thunderbird because it just 'works'. The users at this site would not switch and will cite they have been working in a POP situation on their other Linux box since Adam was a boy.

Any help would be very much appreciated.

I like to think I can do this with my eyes shut by now, but this one has got me stumped.

--

As always, I remain at your service.

Kindest Regards, David.M.Clark (Director - Senior Linux/UNIX Consultant)

Davrom Consulting Pty Ltd E-mail : david@davrom.com PO Box 1644, Sunnybank Hills, 4109 Twitter: @DavidClark1961 ABN: 81 096 990 804 MSN: david@davrom.com Phone/Fax: 61-7-32720267 Skype: dmc1961 Mobile: 0418-763124 Google: dmc1961@gmail.com Podcast: http://www.davrom.com/ldup/ldup_rss.xml =---------------------- http://www.davrom.com -------------------------= Specialising in: Linux (Fedora/RedHat/CentOS), UNIX, SCO, MikroTik, Networking/Internet, E-mail/Web Technologies

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