Re: [exim] SMTP timeout while connected to <x> after sending…

Top Page
Delete this message
Reply to this message
Author: Jakob Hirsch
Date:  
To: James Green
CC: exim-users
Subject: Re: [exim] SMTP timeout while connected to <x> after sending data block
Hi,

> this likely to be an issue at the receiving end, or a networking issue
> between the two hosts, or is it a simple misconfiguration at my end?


could be
- the notorious MTU issue, caused by dumb ICMP filtering (on your side
or the remote, but then they'd have this problem with most sites). Try
to reduce your MTU and see if it helps (e.g. on Linux "ifconfig eth0 mtu
1400" or "ip link set eth0 mtu 1400")
- broken firewall that cannot handle tcp window scaling, see
http://kerneltrap.org/node/6723, if you're using Linux. Try setting
/proc/sys/net/ipv4/tcp_window_scaling to 0
- some other network related problem. Try to capture the sesssion with
tcpdump and analyze the dump with wireshark.