I encountered a problem after the installation was complete.
My environment is apache+php7.3
I have tried to change the php version. This problem has occurred from 5.6 to 8.0. There is no problem with php5.5 and you can log in normally.
The log is below:
[27-Nov-2021 20:22:22 +0800]: <3q2cp4cm> IMAP Error: Login failed for email@example.com against imap.mydomain.com from 18.104.22.168. Could not connect to ssl://imap.mydomain.com:993: Unknown reason in /www/wwwroot/roundcubemail-1.5.0/program/lib/Roundcube/rcube_imap.php on line 211 (POST /?task=login&action=login)