Cloud-based scanning

[Jason Ede]

It's one argument that made greylisting so attractive for a long while (and I think the argument still holds)... 

Steve Freegard of FSL published this... http://www.fortantispam.com/wp-content/uploads/2013/02/greylisting_whitepaper.pdf

Jason


> -----Original Message-----
> From: mailscanner-bounces at lists.mailscanner.info [mailto:mailscanner-
> bounces at lists.mailscanner.info] On Behalf Of Glenn Steen
> Sent: 03 March 2015 15:37
> To: MailScanner discussion
> Subject: Re: Cloud-based scanning
> 
> Well, one problem with doing most any rejections "after the fact" is that you
> may become a "spam reflector", apart from the efficiecy argument
> (rejections are a LOT cheaper than bounces;-).
> ISTR there being a lot of discussion about this about... Ohh... 6?
> years ago. There were some trends in how spammers crafted their filth back
> then ("joe jobs" etc) that made rejections particularily attractive. I suppose
> nothing really has changed on that account.
> 
> Cheers!
> 
> --
> -- Glenn
> 
> On 3 March 2015 at 15:47, Denis Beauchemin
> <Denis.Beauchemin at usherbrooke.ca> wrote:
> > James,
> >
> > Thanks for the info. But if my servers don't send NDRs, people who make a
> typo in the email address of one of our users won't be notified of the error
> and will not be able to retry with the correct email address... This is not
> desirable but on the other hand you are right about address harvesting. And
> if my servers do send NDRs they could be used to joe-job some poor pal.
> >
> > I don't really like both avenues...
> >
> > Thanks.
> >
> > Denis
> >
> > -----Message d'origine-----
> > De : mailscanner-bounces at lists.mailscanner.info
> > [mailto:mailscanner-bounces at lists.mailscanner.info] De la part de
> > James Nelson Envoyé : 3 mars 2015 09:41 À : MailScanner discussion
> > Objet : Re: Cloud-based scanning
> >
> > Denis,
> >
> > I also use office 365 for an edge filtering. Mine is synchronized with
> > my internal active directory via the Microsoft Dirsync tool, but aside
> > from the additional load you will place on your internal servers by
> > not offloading directory based blocking at the office 365 level,
> > there's not technically any harm in what you describe, as long as you
> > configure your internal servers not to send NDRs, which in addition to
> > creating additional traffic can be used by spammers for address
> > validation
> >
> >> On Mar 3, 2015, at 8:22 AM, Denis Beauchemin
> <Denis.Beauchemin at usherbrooke.ca> wrote:
> >>
> >> Hello,
> >>
> >> We are about to move our MX to the cloud in Microsoft 365. The way it
> would work would be to scan the emails there and then deliver them to our
> servers.
> >>
> >> The problem is that we can't for the moment tell MS365 which email
> addresses are valid and which are not (the data is in an LDAP server that is
> not synchronized with our AD). Thus MS365 will be forwarding all harmless
> emails to our internal servers who will reject invalid email addresses.
> >>
> >> I seem to remember this is really not a good idea but I can't remember
> why. Can someone shed some light on this please?
> >>
> >> Thanks.
> >>
> >> Denis
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> 
> 
> --
> -- Glenn
> email: glenn < dot > steen < at > gmail < dot > com
> work: glenn < dot > steen < at > ap1 < dot > se
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