Re: [Exim] firewall and email problems

Pàgina inicial
Delete this message
Reply to this message
Autor: Wakko Warner
Data:  
A: Tom Kistner
CC: exim-users
Assumpte: Re: [Exim] firewall and email problems
> > As I stated before (weeks ago), I'm having problems receiving emails from
> > some hosts through a firewall. The fireall is sonicwall.
>
> So that is your firewall or the other hosts one?


The machine that I got the tcpdump from is the same machine that's running
exim. It's linux 2.4.19 (self compiled from kernel.org no extra patches)

> I see you are on dialup.


It's not. It's DSL. That's the hostname from the ISP.

> Is your mailserver on the router, or behind it?


Mailserver behind it. This sonic wall has 3 ports. WAN DMZ and LAN.
Server is on DMZ and DSL is on WAN.

> What is your MTU size on the uplink? 1500 or smaller?


Uplink? the MTU on eth0 is 1500. I lowered it to 1300 to see if that would
change anything, which it didn't.

> My guess is that the remote ends sends you "please fragment" ICMP
> messages that your firewall is dropping, or vice versa.


From WAN to this machine on DMZ is unrestricted. I specifically asked for
there to be no blocking whatsoever. I do not know if the firewall is
hardcoded with that in mind or not.

--
Lab tests show that use of micro$oft causes cancer in lab animals