Mailscanner generated duplicate message.

[Glenn Steen]

On 24/12/2007, Mark Sapiro <mark at msapiro.net> wrote:
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> Alex Broens wrote:
> >
> >
> >
> >
> > On 12/24/2007 3:23 PM, Mark Sapiro wrote:
> >> Alex Broens wrote:
> >>> probably totally irrelevant yet got a hunch...
> >>>
> >>>
> >>> what are your settings in MailScanner.conf for
> >>>
> >>> Queue Scan Interval
> >>>
> >>> Max Unscanned Messages Per Scan
> >>>
> >>> Max Unsafe Messages Per Scan
> >>
> >>
> >> Queue Scan Interval = 6
> >>
> >> Max Unscanned Messages Per Scan = 30
> >>
> >> Max Unsafe Messages Per Scan = 30
> >>
> >>
> >>> Could it be you're seeing a race condition between scanning threads?
> >>
> >>
> >> This is exactly what the problem seems to be, but I don't know what to
> >> do to prevent it or what I could have done or omitted to cause it.
> >>
> >> I suppose I could set
> >>
> >> Max Children = 1
> >>
> >> but that seems extreme, and it seems if it were necessary, more than
> >> just me would be seeing this problem.
> >
> > Single CPU:
> >
> > Max Children = 5
>
>
> This is what I currently have.
>
>
> > Dual:
> >
> > Max Children = 8
> >
> > (keep the box relaxed till you get the stuff to process)
> >
> > Pls try:
> >
> > Queue Scan Interval = 15
> >
> > Max Unscanned Messages Per Scan = 5
> > Max Unsafe Messages Per Scan = 5
>
>
> I will try these. Note that I will be offline for the next week, so I
> won't be able to report much until after the new year.
>
>
> > You may need to tweek "Queue Scan Interval" to your box's perfomance
> >
> > my rule of thumb:
> >
> > Queue Scan Interval = thread_count + 3
> >
> > keep us posted
>
>
> OK.
>
> Note that logs indicate that this problem has only occurred on mail
> which is not actually scanned because of a 'no' in scan.messages.rules.
> I don't know why this would matter, but it may be significant.
>
> All but one of the occurrences were on outgoing mail from localhost. The
> other one was an incoming message to postmaster. Logs indicate 4 copies
> of this one were delivered and I undoubtedly saw all four but just
> deleted them thinking they were multiple spams
>
> The nature of the server is that outgoing mail is virtually all Mailman
> list posts or forwards of mail, all of which was scanned on the way in.
> I would just as soon not have Postfix hold mail from localhost at all,
> but I haven't figured out how to do that.
>
Bypassing MailScanner for outgoing mail is easily done... All you need
is an smtpd listening on another port .... and have that smtpd _not_
use the header_check... Then see to it that mailman use that port to
submit mails... Set SMTPPORT in your config, IIRC... There are some
examples littering the net, on how to setup a "secondary" smtpd
listener, and you usually have a stub in your master.cf ... Also look
at the wiki, I have some howto there where I use a trick like that to
do multi-recipient splitting (one mail/recipient, so that MailScanner
rules don't work on just the first recipient...). Or give a holler and
I'll dig something out.

Cheers
-- 
-- Glenn
email: glenn < dot > steen < at > gmail < dot > com
work: glenn < dot > steen < at > ap1 < dot > se