Delayed duplicate emails being sent out.

Hi new here.

I am having some issues with sendmail sending out duplicate emails for some of our users. Its not very consistant either. For example some duplicate emails get sent out in 20min intervals some right away. The problem not across the board either only some people are having this issues. We host like 40 virtual sites and so email for most of them. We are also using the latest version of sendmail with interfaces with Blue Quartz server management GUI.
I've poked around the server and cant see anything unusual.
Any ideas?

Thanks in advanced.

well that sucks :S

Welcome to Dev Shed.

What OS are you running?

You mention only some people having problems... are the problems also only with certain domains? Or all domains, but just certain users?

Hi Thank you for the reply. Yes it not all domains but certain ones also now that I look at it We are running CentOS 4.5. WHich is weird I was told the distro was RedHat.
From the feedback I have gotten from users is that only some domains and some users within that domain and its very sporadic. For example my account on the server doesnt get any duplicates or send out any yet my co-worker does get some on the same domain.
I have noticed that when email gets sent out from our outgoing it takes almost a min to send out and in fact sometimes does time out. So maybe that delay is making the server think it timed out and sent it out again?

A couple of things to start looking at here.

1. What is the load on the system when this is happening. Is it possible that sendmails' connection is being dropped, yet the mail got delivered anyway. There is a feature that will cause sendmail to stop delivering when the load gets too high.

2. Examine the system and sendmail logs based on the time and date of the delivery of the original and the dup mail. Look for something that they all have in common.

3. Is it possible that you can get a complete copy of the emails in question and examine the headers to see if there are any clues there?

4. The last piece of advice, and this would be the absolute last thing I would try, is to put sendmail into a more verbose reporting mode. You'll have to examine the docs on this and your own system to make this change.

Cheers - and good luck.

Im not sure if this is helpful but I did run the following

uptime | awk '{print $10 " " $11 " " $12}'

and got this load average

1.47, 1.28, 0.93


To be honest I'm not sure how to interpret this. I do know that haveing a 3.00 or higher load average is bad.

I'm going to check the other tips you suggested.

Looking at the headers I really dont see anything out there. Just that the message ID is different.
Any hints on what Im looking for?

If I remember correctly, sendmail only suspends delivery when the load goes to 10 or above. You will have to examine the sendmail log itself to see if this is happening. I wish I could remember the wording of this to give you something to hunt for.

Running top for a while may help, but that demands your attention.

That's the tough part - what to look for. What is the chance that the mail is actually being sent twice? Is there something in the setup files for the domain(s) in question? Is it always the same user? Take a good look at the sendmail log for message traffic.

While watching the maillogs I noticed I'm getting alot of these type of errors


Apr 3 08:23:40 ws096 spamd[10489]: (Missing operator before
Apr 3 08:23:40 ws096 spamd[10489]:
Apr 3 08:23:40 ws096 spamd[10489]: 1?)
Apr 3 08:23:40 ws096 spamd[10489]: rules: failed to run header tests, skipping some: syntax error at (eval 439) line 11, near ";
Apr 3 08:23:40 ws096 spamd[10489]: }"
Apr 3 08:23:40 ws096 spamd[10489]: Use of uninitialized value in concatenation

I thought this line was interesting

/usr/lib/perl5/vendor_perl/5.8.5/Mail/SpamAssassin/PerMsgStatus.pm line 2669, <GEN216149> line 34.
Apr 3 08:23:40 ws096 last message repeated 2 times
Apr 3 08:23:40 ws096 spamd[10489]: Number found where operator expected at (eval 440) line 10, near "}

Any thoughts?

Looks like you found it. I won't be of any help here as I never used Spam Assassin. The company I worked for used a commercial package for spam and virus detection. Good work on finding it.

Cheers