Tracking Email routing

Andy Bradford amb-plug at
Mon Apr 24 14:48:41 MDT 2006

Thus said Stephen Smith on Mon, 24 Apr 2006 13:41:14 MDT:

> When email do not get delivered, no bounce notices are received and no
> errors are registered.

Where would you  expect bounces to go? Normally they  go to the Envelope
Sender address; is your application setting a sensible one?

> Not being an  email expert, more like  a novice, I could  use a little
> help tracking  down the issues.  Is there an equivalent  to traceroute
> for email, that would diagnosis routing issues?

I don't know  of a traceroute-like tool, however, your  best resource is
going to be the mail logs. If you  don't have good logs, or even easy to
read logs, then you are in for a long debugging. You also need to have a
firm understanding of  what your applications are doing.  Are they using
/usr/lib/sendmail? Are they speaking SMTP with a particular mail server?
What do the logs say?

If you  don't have  good logs, the  next best thing  is tcpdump  or some
other sniffer  that can watch  SMTP traffic.  Capture a message  off the
wire with tcpdump and then use tcptrace to reconstruct it (or ethereal).

[-----------[system uptime]--------------------------------------------]
  2:48pm  up 22 days,  6:10,  1 user,  load average: 1.00, 1.01, 1.00

More information about the PLUG mailing list