The other day I had some problems to send mail at root@raspberrypi.
Example of correct log:
2014-08-26 10:02:38 Start queue run: pid=31708 2014-08-26 10:02:38 End queue run: pid=31708 2014-08-26 10:12:09 1XMDjV-0008Gl-9W pi R=local_user T=mail_spool 2014-08-26 10:12:10 1XMDjV-0008Gl-9W Completed 2014-08-26 10:32:06 1XME2n-0008J7-Ig pi R=local_user T=mail_spool 2014-08-26 10:32:06 1XME2n-0008J7-Ig Completed 2014-08-26 10:32:38 Start queue run: pid=31941 2014-08-26 10:32:39 End queue run: pid=31941Failed log:
2014-08-28 20:02:39 Start queue run: pid=664 2014-08-28 20:02:39 End queue run: pid=664 2014-08-28 20:32:39 Start queue run: pid=3730 2014-08-28 20:32:39 End queue run: pid=3730 2014-08-28 20:50:40 1XN6eV-0001Vu-1N