sendmail is sending duplicate email messages with majordomo list manager

[Paul Mancillas]

I recently upgraded my Linux server from RH 6.1 to RHEL3 so now I am using majordomo 1.94.5 with sendmail 8.12.11 on a RHEL3 Update 4 server. I have a mailing list with about 150 email addresses on it. When I send email to this list several people get duplicate messages. I have tried reducing the CheckpointInterval sendmail option from 10 to 2 and I still have the problem. I have tried increasing the sendmail queue run interval from 1 hour to 4 hours and I still have the problem. There are several other sendmail options that I can change but before I do that I wanted to post this message on this forum. Does anyone know how to fix this problem?

Thanks,
Paul Mancillas

[Bejoy C Alias]

Whether the users who all are getting the duplicate mails are the same everytime . If yes then it may be because of some user level forward files or some mistakes in ur aliases file . After setting CheckpointInterval to 2 , atmost two people should get duplicate messages . If more than 2 users are getting duplicates , then it may not be the problem with this option . Check for any user level forward files .

[Paul Mancillas]

The list of people that get duplicate messages is different for each message that is sent out so I know it's not related to the aliases file. I agree that it's probably not related to the checkpoint interval parameter either because it's usually more than 2 people that get duplicate messages each time. Any more suggestions? Thanks.

[Steven E. Protter]

I recommend verifiying in /var/log/maillog that there are actually two messages going out.

I think that two messages are going out and it may be a function of sendmail thinking the original message did not go through.

This could be due to DNS issues, or configuration problems with sendmail itself.

The messages in maillog will allow us to narrow down the issue.

SEP

[Paul Mancillas]

Steven, you have a good suggestion about /var/log/maillog that I have already investigated. Question, how can you tell from the entries in maillog if the message was sent out once or twice? Thanks.

[Bejoy C Alias]

Check the headers of the duplicate mails to see the smtp id of the messages . It should be same if it was created by the same sendmail process which sent all the duplicates .