Hello there,

I have a problem that i'm trying to sort out in an AIX host. /var/spool/mqueue is full of dead letters but i don't see sendmail running. It's easy to setup a cron job which removes dead letters older than 30 days. But i would like to understand what causes this issue. Any help on this matter is highly appreciated.

$ ls -l | sort -nr | head
total 2030536
-rw-r--r-- 1 root system 866283 Jun 24 00:29 dft5O0TLkZ2159082
-rw-r--r-- 1 root system 438772 Jun 23 00:30 dft5N0UGhm1401160
-rw-r--r-- 1 root system 354809 Aug 09 00:34 dft790YfeI823578
-rw-r--r-- 1 root system 320232 May 29 01:32 dft4T1WTgm2031790
-rw-r--r-- 1 root system 293545 Jul 12 00:33 dft6C0X2sJ1651120
-rw-r--r-- 1 root system 279479 Jul 05 00:35 dft650Zctx1208820
-rw-r--r-- 1 root system 244257 May 12 00:28 dft4C0S0QL1986992
-rw-r--r-- 1 root system 230103 Aug 02 00:34 dft720Y6SG1081710
-rw-r--r-- 1 root system 224729 Aug 07 00:29 dft770TYnN1491260

$ pwd
/var/spool/mqueue
$ du -sg .
0.98 .


$ ps -ef | grep -i sendmail | grep -v grep
$


Thanks

You should check the content of the letters. Cron, for example, sends you the output of the executed commands in email (if there is such output -- cf: redirection).

1 members found this post helpful.

Hi there,

Regarding the mail queue, besides looking inside those files to try and identify their origin as NevemTeve suggested, you might also want to look at the output of the "mailq" command, as this may give you a clue about why they end up there (i.e. could not be delivered).

Even without the sendmail daemon running, you can retry the delivery by running "/usr/sbin/sendmail -q".

Just a comment about the sendmail daemon: it does not need to be running for local mail delivery to work (for example output from cron jobs, or mail send to a local user with the mail/mailx/etc commands), or for you to send mail from AIX to a remote server. It only really needs to run as a daemon if you want to accept SMTP connections (most likely from other hosts). On many (most?) servers this is not required. I routinely stop the daemon to improve security. The daemon does also retry sending message in the queue from time to time - I take care of that by just scheduling a cron job to run "sendmail -q" every 30 minutes.

2 members found this post helpful.

Hello NevemTeve, cliffordw,

Thank you for your reply. It's exactly like you said. These are outputs from cronjobs which are being mailed to local user/root.
Sendmail is not running. Seems like SMTP is required to connect a relay server and deliver these messages. For some reason, both sendmail and SMTP is disabled in my domain. I guess its best to leave as it is and include a job to delete older files.

$ lssrc -s sendmail
Subsystem Group PID Status
sendmail mail inoperative


Thank you so much for posting your suggestions. cheers mates.

Hi,

For cron jobs, if you don't want them to email the output, a suggestion: change the cron jobs to redirect their output to a log file instead.

Regards,

Clifford

Hello Clifford,

Sorry i couldn't reply you soon. Yes, that's an option too. I'll probably include logrotate to compress and rotate the output.

Thank you so much for your time.