Some more tests:
$ openssl s_client -connect tribu.fr:993
CONNECTED(00000003)
* OK [CAPABILITY IMAP4rev1 LITERAL+ SASL-IR LOGIN-REFERRALS ID ENABLE IDLE AUTH=PLAIN AUTH=LOGIN] Dovecot ready!!
a1 LOGIN thibaut passwd
a1 NO [AUTHENTICATIONFAILED] Authentication failed.
On the server side, not much:
Jun 8 21:02:25 yunohost dovecot: imap-login: Aborted login (auth failed, 1 attempts in 54 secs): user=<thibaut>, method=PLAIN, rip=192.168.0.254, lip=192.168.0.86, TLS, session=<uVUrnMo0IADAqAD+>
I checked the /etc/dovecot/dovecot-ldap.conf.ext file but not sure if anything is wrong in there…
I tryed to connect on roundcube directly (whithout the sso connection) and I get the same error:
Jun 8 21:11:55 yunohost dovecot: imap-login: Disconnected (auth failed, 1 attempts in 2 secs): user=<thibaut>, method=PLAIN, rip=::1, lip=::1, secured, session=<gfo0wco0MgAAAAAAAAAAAAAAAAAAAAAB>
Is it linked to the imap auth problem?