Corrupt mail files

[david-8uUts6sDVDvs2Lz0fTdYFQ at public.gmane.org (david-8uUts6sDVDvs2Lz0fTdYFQ at public.gmane.org)]

> david-8uUts6sDVDvs2Lz0fTdYFQ at public.gmane.org wrote:
>> The beginning of the file is a series of zeroes...
>> ~# od -ch /var/mail/susan | head -10
>> \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0  \0
>> (StrongMail Ente
>> rprise 3.2.3.3(3
>> .00.320)); Thu,
>> 11 Jun 2009 09:0
>
> It looks like not only is the start of the message overwritten with a
> string of 16 nulls, but the remainder of the string appears to be a
> Received line, with no sign of the From_ line (typically longer than 16
> bytes), so it looks like the message is truncated as well (or the From_
> line was missing).

Yes, a whole lot of the beginning of the got chopped off, much more than
the handful of zeros.  I neglected to mention that.  Fortunately, I
instituted frequent automatic backups of the mail files after the first
time.

>> - It could be that I'm using ext4, which might not have been a smart
>> thing.
>
> This, or a hardware problem, seems most likely, given the mail tools are
> all fairly mature and reliable. You might want to test this out
> temporarily by symlinking the spool to another file system or an NFS
> mount.

That's an excellent suggestion. My MythTV recording partitions are still
ext3.  I'll look up tonight, but I assume there's a way to convert an ext4
partition to ext3.

>
> I've been seeing mention of ext4 problems in Ubuntu bug reports. 9.04 is
> shaping up to be rather buggy.

This is really the only problem I've seen.  I've had problems with dual
monitors, but I'm guessing that's xorg and not Ubuntu.

>> - It could be procmail, but that seems unlikely to me. .procmail doesn't
>> even have an explicit thing that writes to /var/mail/susan.
>
> If procmail is being used for local delivery, then it will implicitly
> write to the spool. Check your postfix master.cf to see what local
> delivery agent is being used.

I'm relatively sure it's procmail, but I'll check.

> I'd hold off on the conversion until you've tracked down the source of
> your corruption.  Once that's behind you, consider switching to
> Dovecot's deliver as your LDA, unless you have a lot of custom procmail
> filtering you don't want to convert to Seive.

But what if using mbox is the problem?

I have *A LOT* of procmail rules, but I'm willing to use something else if
it's better.  I'll google tonight, though "deliver" is hard to google on. 
How is it better?

Thanks.