The Exchange takeover, stealth Mailscanner, SPF, and other thoughts. Subj was: Re: help me

Alex Crow alex at
Fri Oct 15 17:24:42 IST 2010


However that might not play out quite as well as just letting them shoot 
themselves in the foot - if you put a "stealth" MS box in front of 
Exchange, then management would just think that the Microsoft stuff did 
just as well as the old Linux software. It might be better to explain it 
should be tested with and without the Mailscanner solution as a 
comparison. However if Nigel is leaving, why not just let them fight 
their own war!

Nigel, I presumed you pointed out that in addition to the £16k for 
exchange they would need something to stem the spam-flow, and given 
their need for "a throat to squeeze" (the usual reason) it would 
probably be commercial?

Using SPF, Greylisting and MS I think I'd guess we're blocking 99.5-ish% 
of all spam and the of the remaining .5%, a good three-quarters is 
getting 6 SA points or more. I'm almost getting confident enough to drop 
the "high-scoring SPAM" level down and also the marking threshold. Does 
anyone have any figures (rough or otherwise) or experiences about such 
adjustments (I was thinking to take high-score to 8 and marking as 
possible spam down to 5 or even 4).

BTW, after deploying SPF checks I was shocked to find at least one major 
UK and international finance house has a badly configured SPF record (ie 
not all outbound sources in the record, and a "-all" rule ending.) As a 
hint their "old" (sensible) name suggests they hail from somewhere east 
of Peterborough.



On 15/10/10 11:28, Martin Hepworth wrote:
> Nigel
> so keep MS infront of the scary M$-Exchange stuff so keep all the bad 
> stuff off the email servers. be interesting to see how much spam/cost 
> a commercial version does. (hey if the want commercials there's always 
> FSL;-)
> -- 
> Martin Hepworth
> Oxford, UK
> On 15 October 2010 09:14, Nigel Kendrick 
> <support-lists at 
> <mailto:support-lists at>> wrote:
>     Sadly I may be going off list too. Not that I want to, but our
>     company was bought out and the new owners find Linux 'scary stuff'
>     and so they have decided to take our 3 main Linux mail platforms
>     and move them to their comfort zone (MS Exchange) - I estimate
>     that's £16K in client licences for Exchange alone! Don't ask - I
>     have briefed them, drawn up a cost benefit analysis and encouraged
>     them to do a SWOT analysis on our whole, extensive, Linux
>     infrastructure but they cannot get the Board out of the 'Microsoft
>     or bust' mentality.
>     It's a great shame as MailScanner is a great app and the List is
>     full of great, helpful people. The only saving grace is that I am
>     moving to a hi-tech electronics/comms company as IT Manager and
>     they are already heavily into Linux for in-house apps and as the
>     core of one of their products and one of my first tasks is
>     evaluate their creaking IT infrastructure so their Exchange server
>     is up for a fitness review!
>     Two weeks to go as I watch the empire around me crumble!
>     Keep up the good work and I'll see you all somewhere else.
>     Nigel Kendrick
>     --
>     MailScanner mailing list
>     mailscanner at
>     <mailto:mailscanner at>
>     Before posting, read
>     Support MailScanner development - buy the book off the website!

-------------- next part --------------
An HTML attachment was scrubbed...

More information about the MailScanner mailing list