> On Dec 26, 2017, at 6:52 AM, Dominic Raferd <domi...@timedicer.co.uk> wrote:
>
> An expert can answer, but it would be bizarre behaviour if true. I
> rather assume that postfix continues to accept incoming mails, and
> queues any that are destined for the locked local file until postlock
> releases its exclusive lock.
Inbound mail continues, some local(8) deliveries may be briefly delayed
waiting for a lock, all other deliveries will continue. The locks should
be held very briefly, just long enough to copy each file. Attempts to
lock multiple files can deadlock (though not with Postfix delivery agents
which do not lock multiple files). Lock a file, back it up promptly,
release that file's lock and move on to the next.
--
Viktor.
