[Dovecot] Dovecot configuration and question about IP trusted

[Mik J]

Hello list,

I've just finished to install Dovecot and things seems to work so far. After some little efforts though.
My version is 2.0.20


Question 1:

I'm trying to tighten the security a little bit and added in dovecot.conf

login_trusted_networks = 192.168.1.0/30
Then restarted Dovecot


My client has the IP 192.168.1.20 and it's still able to retrieve emails. I expected it to be forbidden. Am I missing something ?

# dovecot -n | grep trust
login_trusted_networks = 192.168.1.0/30



Question 2:
I feel that Dovecot is slow. I'm doing my test with my iphone as an imap client.
Test 1: I retrieve a mail on a remote server provided by a hosting company, it takes 2 seconds
Test 2: I retrieve a mail on my server which is on my LAN, the mail includes a few letters in the subject and a few letters in the body. The action takes about 8 seconds.
It's quite subtule to measure so first I would like to know if Dovecot tries to do a dns reverse lookup or something like that. And it would explain the overhead.

Thank you