sending mail with attachments always fails (FreeBSD/pf)

[olli hauer]

Victor Lyapunov wrote:
> Hi all,
> 
> I have production network with FreeBSD box acting as firewall. The
> problem emerge as soon as users send mail with attachments. (Sending
> mail without attachments always succeeds). Basically, when a user
> tries to send a message, only part of it transmitted before connection
> is interrupted and sending fails. The problem persists only when pf is
> enabled.
> 
> My ruleset:
> scrub in all fragment reassemble
> block drop on em0 all
> pass inet proto tcp from 192.168.0.0/24 to any port = smtp flags S/SA keep state
> pass inet proto tcp from 192.168.0.0/24 to any port = pop3 flags S/SA keep state
> pass inet proto tcp from 192.168.0.0/24 to any port = imap flags S/SA keep state
> pass inet proto tcp from 192.168.0.0/24 to any port = smtps flags S/SA
> keep state
> pass inet proto tcp from 192.168.0.0/24 to any port = pop3s flags S/SA
> keep state
> pass proto udp from any to any port = domain keep state
> 

[...]

Is this only for client submitting (imap) or even for incoming mails 
from outside via smtp?

What about outgoing traffic from the machine?

Try the following in pf.conf to see why this happens

set loginterface pflog0
set block-policy drop
set skip on lo0

block drop in log on em0 all
pass out log on em0 all

Now use tcpdump to see which rule drops the traffic
#> tcpdump -net -i pflog0

--
olli