mailq - help on understanding - any action needed?


This message below was from running mailq command.
I am wondering if this is someone trying to send mail from the server? (i dont know

Just trying to interpret this correctly… (I have spf records as strict and disallow others and auth on smtp setup.)

0ECC46150A 22906 Thu Jan 26 08:40:41
(host[] said: 452 4.3.1 Insufficient system resources (in reply to MAIL FROM command))

– 22 Kbytes in 1 Request.

Thanks a lot!


So the domain “” is part of your server, right?

If so, that certainly is an unusual error…

What output do you get if you run this command:

free -m

Also, are you on a VPS of some sort, or is this a dedicated server?


Hey Eric,
no, the waterdog domain is completely unknown to me and therefor should not be allowed to send mail at all…

It is a dedicated server.

[root@mail01 ~]# uptime 13:36:00 up 18 days, 22:22, 2 users, load average: 0.00, 0.00, 0.00 [root@mail01 ~]# free -m total used free shared buffers cached Mem: 3960 2790 1170 0 305 1093 -/+ buffers/cache: 1391 2569 Swap: 6015 2 6013 [root@mail01 ~]#

Aha, that makes more sense.

That just means that someone tried to send an email to a remote server, and the remote server is having a resource problem at the moment.

That message will sit in your queue until the remote server is available to accept the message.


OK cool… just wanted to be sure my smtp security was not breached somehow…