Postfix thinks there isn't enough disk space in a jail

[Ralf Härle]

> Out: 220 xx ESMTP
> In:  EHLO yy
> Out: 250-xx
> Out: 250-PIPELINING
> Out: 250-SIZE 1024000000
> Out: 250-VRFY
> Out: 250-ETRN
> Out: 250 8BITMIME
> In:  MAIL FROM:<a at b.com 
> <http://lists.freebsd.org/mailman/listinfo/freebsd-questions>> SIZE=13414
> Out: 452 Insufficient system storage
> In:  QUIT
> Out: 221 Bye


> Okay, so the disk is filling up.


This happens, if there's less than 2*message_size_limit free space on 
/var/mail.
Check /var/log/mail

> box# df -hl
> Filesystem    Size   Used  Avail Capacity  Mounted on
> /dev/ar0s1a  1008M    45M   882M     5%    /
> /dev/ar0s1d    27G    23G   1.9G    92%    /jails
> /dev/ar0s1h  1008M    20M   908M     2%    /home
> /dev/ar0s1g  1008M  10.0K   927M     0%    /tmp
> /dev/ar0s1f   3.9G   1.2G   2.4G    34%    /usr
> /dev/ar0s1e   2.0G   148M   1.7G     8%    /var
> procfs        4.0K   4.0K     0B   100%    /proc
> procfs        4.0K   4.0K     0B   100%    /jails/xxx/proc


> Okay, we are at 92%. We should clean some things up, but we do still have
> 1.9GB of free space. (And we often linger around this anyway.)


> Postfix is set to accept mail as long as there is 25MB of free space:


> main.cf:queue_minfree = 25000000


That doesn't matter. Check your main.cf. What message_size_limit have 
you defined?
I guess, your /var is getting temporarly quit full due to some cronjobs 
e.g. backup-scripts which need a lot of temp-space to zip big 
directories like /home.

Greets!
Ralf ;-)