Solved.

In the errors.log of RC there was a line I didn't see before (my bad):
Peer certificate CN=`mail.xxxx.lan' did not match expected CN=`imap.xxxx.lan'

The dovecot certificate is for mail.xxxx.lan and in the RC config file there was imap.xxxx.lan

After changing that in the RC config file I could login using RC.
Also changed imap_auth_type from LOGIN to PLAIN.
Don't know if that is necessary or not.

Thanks for your help.

OK that's helpful, I think we're past the issue with the certificate. Can you try changing your imap host from ssl://... to tls://... and see if that works?

The error changed after I changed the the permission.
Setting verify_peer to false didn't make any difference.

Never logged in successfully with Roundcube. Thunderbird works.

Contact your email provider to see if they can recover the email from a backup.

Salut
j'ai eu un bloquage sur ma boîte email, et j'ai constaté que j'ai tout perdu
et ma boîte de réception est vidée.

sil vous plait rassurez moi que je peux récupérer tout mes courriels

c'est important , mes échanges avec médecins et assurances et travail....

I will. Thank you.

Quote from: SKaero on November 29, 2025, 01:09:31 PMThat error is coming from your mail server. Contact your email provider and ask them why outgoing mail is suspended.

The username and password where striped from the log for the plain authentication, so its not helpful. Maybe try enabling:
// Log successful/failed logins to <log_dir>/userlogins.log or to syslog
$config['log_logins'] = false;
That should have the username that is trying to login.

Here is what I was able to log, doesnt seem very helpful but I may be mistaken.

[01-Dec-2025 14:08:27 +0000]: <gti8d2q7> [535C] C: A0001 AUTHENTICATE PLAIN ****** [53]
[01-Dec-2025 14:08:31 +0000]: <gti8d2q7> [535C] S: A0001 NO [AUTHENTICATIONFAILED] Authentication failed.
[01-Dec-2025 14:08:36 +0000]: <gti8d2q7> [73B6] Connecting to [DOMAIN REDACTED]:143...
[01-Dec-2025 14:08:36 +0000]: <gti8d2q7> [73B6] S: * OK [CAPABILITY IMAP4rev1 SASL-IR LOGIN-REFERRALS ID ENABLE IDLE LITERAL+ STARTTLS AUTH=PLAIN AUTH=LOGIN]
Dovecot (Ubuntu) ready.
[01-Dec-2025 14:08:36 +0000]: <gti8d2q7> [73B6] C: A0001 AUTHENTICATE PLAIN ****** [61]
[01-Dec-2025 14:08:44 +0000]: <gti8d2q7> [73B6] S: A0001 NO [AUTHENTICATIONFAILED] Authentication failed.

That is a different error but not very informative. Just to be sure if you set verify_peer to false it does connect correct?

If you do not have access to the server that Roundcube is hosted on then you will not be able to add or enable any plugins.