Server Error: STATUS: Internal error occurred Refer to server log for more information.

if you are seeing this error on Roundcube, your mail folder ownerships are messed up.

Don’t worry,do the below steps as root via SSH.

If the email account is info@domain.com

check the username of the domain and access the directory

/home/username/mail/domain.com

chnage all the ownership of the directories recursively using the below step. (info is the folder of mail account)

chown -R user. info

chown user.mail maildirsize