Dovecot Operation Modes

Dovecot Backend

Dovecot can be configured for use in "backend" mode on a single server. In this mode, Dovecot is responsible for reading and writing mails to storage and handling all of the email protocols.

Dovecot Proxy

Dovecot can be configured for use in "proxy" mode on a single server. In this mode, Dovecot is responsible for proxying incoming email protocols to remote hosts.

See proxy passdb.