Re: replacing sanitizer w/ amavisd-new
Thanks for your discussion.
One correction, the muttering about "unsupported methods" is actually
from:
http://www.postfix.org/addon.html#content
which is perhaps slightly more creditable than geocities.
Googling around a bit I got this thread with thoughts from one of
the main developers (Wietse Venema)
http://archives.neohapsis.com/archives/postfix/2003-08/0511.html
http://archives.neohapsis.com/archives/postfix/2003-08/0513.html
http://archives.neohapsis.com/archives/postfix/2003-08/0514.html
http://archives.neohapsis.com/archives/postfix/2003-08/0515.html
http://archives.neohapsis.com/archives/postfix/2003-08/0522.html
http://archives.neohapsis.com/archives/postfix/2003-08/0595.html
[the threading at the archive was not good so I included links to whole
thread]
I might feel differently if our server was heavily burdened, but the
prospect of breaking things with an upgrade to postfix not worth the
speed.
############3
On Sat, 10 Jan 2004, Michael Loftis wrote:
>
>
> --On Saturday, January 10, 2004 21:53 -0500 Dan MacNeil
> <omacneil@brave.cs.uml.edu> wrote:
>
> >
> > Thanks for your reply.
> >
> >> Might I suggest MailScanner?
> >
> > You might, some specific problems with amavisd-new that aren't present in
> > MailScanner might be even more helpful.
> >
> > At:
> > http://www.geocities.com/scottlhenderson/spamfilter.html
> >
> > they say:
> >
> ># mailscanner system, works with Postfix and other MTAs. This
> > uses unsupported methods to manipulate Postfix queue files, and there are
> > multiple reports of message duplication and/or delivery of truncated
> > messages.
>
> It isn't exactly supported nor unsupported....Basically it relies on the
> fact that postfix can be told to use deferred transports on inbound,
> automatically forcing everything to go into the deferred queue. You run
> one copy of postfix in that mode. Another in a normal mode, minus
> smtp/incoming mail. I haven't had any problems with truncated email nor
> duplicate deliveries at all with recent-ish Postfix. MAilscanner monitors
> the deferred queue, pulling messages out of there and working on them,
> putting them into the inbound pickup area on the other postfix instance
> after processing. The sytem works well and is quick.
>
> I don't see how postfix could be responsible for multiple deliveries in
> this scenario, nor how mailscanner would cause it. The only time that sort
> of thing would happen is for people who don't follow the instructions and
> don't put the three queues (mailscanner, inbound postfix, outbound postfix)
> on the same partition/filesystem. This is a MUST. mailscanner simply
> relinks the files into/out of work areas, this is fast, and atomic,
> assuming it's on the same filesystem. Otherwise if it's not the same
> filesystem you have to copy to/from staging areas to achieve the atomicity.
>
>
> MailScanner catches about 30% more 'dangerous content' and virii than
> amavisd-new given the same virus scanner because MS seems to unpack more
> thoroughly/properly. MS supports/integrates the update system of all the
> virus scanners it supports negating the need to run a separate update
> cronjob all the time. MS supports throttles, amavisd does not, and so MS
> will be much nicer to an overloaded/very briskly loaded system than
> amavisd. amvisd requires copying the message multiple times, MS reduces
> this by using the link/unlink method that all mailservers use nowadays
> internally to their queues.
>
> MS does require running two separate copies of postfix, that amavisd does
> not. There's a point for amavis. amavis eliminates unnecesary code from
> the resultant script at ./configure time, MailScanner doesn't. That said
> though MailScanner seems to work faster on my system.
>
> Not sure how much else to go on about this.
>
> --
> Michael Loftis
> Modwest Sr. Systems Administrator
> Powerful, Affordable Web Hosting
>
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