I'm slowly setting up an email system on a Centos 7 server. The particular software I'm using will consist of postfix, dovecot and roundcube, although my question isn't specific to them (I think).
I've gotten to the point where postfix and dovecot are working and now I just need to add the webmail (roundcube). It occurred to me that instead of connecting it via a standard TCP/IP IMAP port I could instead use a unix socket. In theory, that should give me better performance/lower overhead, right? I could even close the port 143 entirely, forcing my users to use an encrypted connection (better security), while leaving the unencrypted socket for local access by the webmail (better performance). As far as I can tell, both dovecot and roundcube can be configured in this fashion, but there is no indication that anyone has ever attempted that. Why is that? Am I missing something?