Unable to login to Horde [User * is not authorized for Mail (Host: *)]

Operating System & Version
CloudLinux 7.7
cPanel & WHM Version
86.0.17

MH-Stefan

Member
Dec 3, 2013
24
2
53
cPanel Access Level
Root Administrator
Hello,

Today a client has reached out to us that he cannot login to Horde through Webmail from a newly created email account. When attempting to open Horde, the following error appears:

User [email protected] is not authorized for Mail (Host: some.host.com)
(The actual values are replaced for privacy reasons, of course.)

I've searched through all relevant logs (cpanel, exim, dovecot, csf and imunify360 logs) and couldn't find anything that could be related to this. His IP address is whitelisted in CSF and Imunify360. cPHulk is disabled.

The client has tried to login from different computers, different browsers and different locations. cPanel, RoundCube, the calendar, contacts are all accessible from his side, only Horde doesn't work.

I was unable to reproduce this error from my side. I've created test email accounts and all of them were able to access Horde.

Is there any specific reason why this error would appear only from the client's end, even while his IPs are whitelisted?

The server runs cPanel v86.0.17, Exim, Dovecot, CloudLinux, Imunify360 with all updates.
 

MH-Stefan

Member
Dec 3, 2013
24
2
53
cPanel Access Level
Root Administrator
Thanks for the suggestion, but that's not the case. All his email accounts are unrestricted and accessible through other Webmail clients and IMAP. Seems to affect just Horde.
 

MH-Stefan

Member
Dec 3, 2013
24
2
53
cPanel Access Level
Root Administrator
The root of the issue has been found. Somehow the characters in the password were transformed to a German umlaut (ä), causing Horde to decline access. Strange that Webmail and RoundCube worked, but anyway... It was much easier than it seemed. :)

So in case someone else has this issue:
Try to use a different password with different special characters.