Bug#796524: Exim4 has stale filehandle after logrotate

[Andreas Pflug]

Sorry for the glitch, searched for keyword logrotate...
Actually, it IS documented that mainlog may stay open unused for a
prolonged time (>2d). I don't think that's too sensible, keeping a
possibly large file open when it's already zipped and deleted...
Conclusion:
Unexpected but documented exim4 behaviour, normal result if logrotate
reloads exim4 as it does with many other apps.