[H-GEN] sendmail timeout problem

[Robert Brockway]

On Fri, 12 Dec 2003 johannes at paradise.net.nz wrote:

> Running sendmail 8.11.6 essentially works just fine except a couple of domains
> do consistently time out with the message "Deferred: Connection timed out
> with smtp.domain, or smtp2.domain"

Try this:

cat /proc/sys/net/ipv4/tcp_ecn

If you get a 1 come back, then set it to be 0:

echo 0 > /proc/sys/net/ipv4/tcp_ecn

If you use ecn some remote routers will go gaga on you.  I've seen this
exhibit as "truly bizarre" mail problems.

Also, could you have a problem wityh PMTU (path mtu) discovery?  Are you
using ADSL (which is renouned for PMTU problems).  This will exhibit as
large mails failing but small mails working.

Rob

-- 
Robert Brockway B.Sc. email: robert at timetraveller.org, zzbrock at uqconnect.net
Linux counter project ID #16440 (http://counter.li.org)
"The earth is but one country and mankind its citizens" -Baha'u'llah