[Fwd: mail delay and can't parse message]

[Julian Field]

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At 00:00 04/04/2002, you wrote:
>On Wed, Apr 03, 2002 at 03:13:26PM -0600, Peter Valian wrote:
>
> > However, Im getting many calls from users claiming that some email is
> > delayed by several hours.  I have not personally witnessed this
> > phenomenon but it's more than just a couple users making this
> > claim...(they claim to receive mail as normal but then every now and
> > again get a message timestamped before several emails they have already
> > received.  I don't know if the problem is with Mailscanner/Sendmail or
> > with Qpopper (4.0.3).
>
>You need to have a look at the messages in question, and see where the
>delay is actually occuring, if indeed it is (you often find that if the
>sending system has its clock set wrong then it appears at first to have
>been delayed, but when you look at the headers, you see that in fact there
>has probably been no delay).
>
> > Also, several warnings a day get sent to postmaster about 'could not
> > parse message xxx, e.g.
> >   Report: Could not parse message g313LlZ19901
> >
> > I don't know if these messages just got dropped or went through or what.
>
>Try it or check your logs; I can't remember off the top of my head what
>the answer is...

There is an option in mailscanner.conf to deliver unparsable TNEF messages
or not.

> > attached is my conf.  One thing that's special to our set up is that the
> > mail spools are NFS mounted...so perhaps some file locking issues?
>
>Since you appear to be running sendmail, it's probably a bad idea to run
>with the spools NFS mounted, as so far as I am aware:
>
>1) Sendmail uses flock();
>2) flock() is not NFS-safe.
>
>I'm not too hot on the details of this though, as sendmail is not my preferred
>MTA.

If using sendmail, you *really* shouldn't NFS-mount your mail spool. As
Nick pointed out, sendmail uses a locking strategy that is incompatible
with NFS. You are effectively running sendmail with no file locking at all,
which is a very bad thing.

--
Julian Field                Teaching Systems Manager
jkf at ecs.soton.ac.uk         Dept. of Electronics & Computer Science
Tel. 023 8059 2817          University of Southampton
                             Southampton SO17 1BJ
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