MS Outlook: Outlook cannot connect to folder inbox from the IMAP email server

Operating System & Version
CentOS 7.9
cPanel & WHM Version
102.0.26

martin MHC

Well-Known Member
Sep 14, 2016
345
75
78
UK
cPanel Access Level
Root Administrator
There are a couple of clients this morning who are unable to access their emails via their Outlook. This is different clients on different accounts -- the server logs show that their imap-login executes ok, and then immediately exits;

Var/log/maillog:

Dec 9 15:12:00 basic dovecot: imap-login: Login: user=<[email protected]>, method=PLAIN, rip=111.222.333.444, lip=555.666.777.888, mpid=16651, TLS, session=<Xg9Fk2bvBsVcE/QT>
Dec 9 15:12:00 basic dovecot: imap([email protected])<16651><Xg9Fk2bvBsVcE/QT>: Disconnected: Logged out in=76, out=1250, bytes=76/1250


They are not blocked on any part of the server as far as I can see (firewall, LFD, exim, etc.) .

This is a sudden issue and seems specific to MS Outlook connecting to the server, the clients claim that they're unable to view their mailboxes in Outlook and that Outlook presents a superficial bland error message.

> Outlook cannot connect to folder inbox from the IMAP email server for account no .............

Are there any good ideas if there's anything we can do to help things from the server end?

We are not aware of any server changes aside from update from 102.0.25 to 102.0.26 a few days ago.
 

cPanelWilliam

Administrator
Staff member
Mar 13, 2018
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Houston
cPanel Access Level
Root Administrator
Hi! Usually, this type of error is related to the email client configuration, but not always. Based on your reply, I assume that you've already checked whether the clients are blocked in cPHulk (if it's enabled). I suggest finding out what settings your clients use that cannot connect (incoming/outgoing email server, ports etc.). It's possible they are using a server name that no longer resolves, a blocked port, or something similar that's preventing the clients from connecting.
 

martin MHC

Well-Known Member
Sep 14, 2016
345
75
78
UK
cPanel Access Level
Root Administrator
Hi! Usually, this type of error is related to the email client configuration, but not always. Based on your reply, I assume that you've already checked whether the clients are blocked in cPHulk (if it's enabled). I suggest finding out what settings your clients use that cannot connect (incoming/outgoing email server, ports etc.). It's possible they are using a server name that no longer resolves, a blocked port, or something similar that's preventing the clients from connecting.
I totally get that, and yes I have checked the usual server side blockers; nothing has changed on the server or DNS wise for the accounts that are now unable to connect, the only common denominator I can see is it's versions of Outlook, queries with the CPHULK etc would be that if the IP is blocked for whatever reason then surely the var/log/maillog file should not have any connection, the fact there's lots of connections that immediately disconnect leads me to believe it's a end point / Outlook issue but I wanted to double check what else can be done at the server end to confirm this.

Cheers
 

cPanelWilliam

Administrator
Staff member
Mar 13, 2018
221
41
153
Houston
cPanel Access Level
Root Administrator
Hi,

the fact there's lots of connections that immediately disconnect leads me to believe it's a end point / Outlook issue but I wanted to double check what else can be done at the server end to confirm this.
Checking the maillog and the exim_mainlog is usually the main step to confirm whether there are any server-side issues regarding the Outlook connection. Since you've already checked the obvious causes I would suggest opening a ticket so our team can access the server to see if anything is being overlooked.
 
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martin MHC

Well-Known Member
Sep 14, 2016
345
75
78
UK
cPanel Access Level
Root Administrator
Hi,



Checking the maillog and the exim_mainlog is usually the main step to confirm whether there are any server-side issues regarding the Outlook connection. Since you've already checked the obvious causes I would suggest opening a ticket so our team can access the server to see if anything is being overlooked.
Hi @cPanelWilliam I have started the process of creating a support ticket however it appears to be hanging at https://support.cpanel.net/hc/en-us/signin with three black dots rotating around the screen and not progressing after asking for my support area authentication. This has been hanging for several minutes like this. Any help progressing this would be appreciated.

The support area was reached via the server WHM root login --> Home / Support / Create Support Ticket route.
 

alanstar

Member
Jun 22, 2022
20
3
3
UK
cPanel Access Level
Root Administrator
We are not aware of any server changes aside from update from 102.0.25 to 102.0.26 a few days ago.
We are currently on 102.0.25 and I came across this post when searching for feedback about 102.0.26 before going ahead with the update. We use EXIM to send emails so this issue gave me some cause for concern. Has there been any progress?
 

mtindor

Well-Known Member
Sep 14, 2004
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343
inside a catfish
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IT's probably just silly old Outlook. When the PSTs get corrupted, all sorts of crazy things happen. And PSTs often get corrupted.
 

alanstar

Member
Jun 22, 2022
20
3
3
UK
cPanel Access Level
Root Administrator
IT's probably just silly old Outlook. When the PSTs get corrupted, all sorts of crazy things happen. And PSTs often get corrupted.
I hope that is the case. We don't use Outlook with this server but do use Exim for sending emails from our websites so I would like to be reasured that there is no risk in updating to 102.0.26 - I haven't found any other negative comments about this release so hopefully it is nothing to worry about. Maybe @cPRex or someone will confirm.