In my /var/log/mail.log I saw the following error:
Aug 6 17:12:58 Nephtys cyrus/imap[6411]: SQUAT failed to open index file
Aug 6 17:12:58 Nephtys cyrus/imap[6411]: SQUAT failed
In order to fix this execute the following commands:
# sudo su cyrus
This will make you the cyrus user.
Now execute
# squatter
This will index all your e-mails (more info by executing $ man squatter). This index is not incremental so you need to run this task once in a while. It might be usefull to create a cronjob for this command.
Linux
cyrus, mailserver, squat, Ubuntu
When I opened Roundcube, the login screen asked me every time for a server name. This turned out to be pretty annoying since this is localhost all the time. In order to remove this field open /etc/roundcube/main.inc.php in your favorite texteditor and set the property
$rcmail_config['default_host'] = ‘localhost’;
Refresh your page and the server textbox has been disappeared.

Linux
mailserver, roundcube, Ubuntu
Virtual domains can be used to route e-mails from multiple domains to the correct mailboxes. In order to make it work, some changes need to be made.
First we need to edit the main.cf (on my Ubuntu server in /etc/postfix/) and add the following lines:
Read more…
Linux
Linux, mailserver, postfix, Ubuntu
After checking out my mail logs I had the following error:
Aug 6 11:38:52 Nephtys postfix/lmtp[3990]: DD69A18A90C: to=, relay=none,
delay=593, delays=593/0.02/0.01/0, dsn=4.4.1, status=deferred
(connect to localhost[/var/run/cyrus/socket/lmtp]: Permission denied)
I Googled the error but could not find a fix. Finally it turned out that the postfix user was not in the mail group, which could be fixed by executing
# adduser postfix mail
Linux
cyrus, mailserver, postfix, Ubuntu