mail/dovecot/10-master.conf

protocols = imap lmtp

service imap-login {
  inet_listener imap {
  }
}

service lmtp {
  inet_listener lmtp {
    port = 24
  }
}

service imap {
}

service auth {
  unix_listener auth-userdb {
  }

  inet_listener {
    port = 100
  }
}