MS Gateway for Exchange 2013 - Any LDAP documentation?

Kevin Miller kevin.miller at
Tue Aug 11 22:50:02 UTC 2015

The problem with 2013 is that it rejects after the DATA phase, meaning that the connection with the sending server is long gone by the time the reject happens.  This, of course, leads to blowback to innocent users.   

I have my MailScanner gateways pointing at my old exchange 07 server to do recipient validation with SMF-SAV.  It's an extra hop but it works.  Microsoft did away with the edge transport in 2013, but has just recently reintroduced it.  See - we're going to toss one in the mix so we can reclaim the Exchange 07 box.  Typical Microsoft to take two years to fix something so wantonly broken.  But at least they *finally* read the memo.  Or, more specifically, the RFC.

On my new postfix boxes I'm using (google it).  I massage the output to only include the addresses I want available to the public, then write that to the recipient table.  I run it nightly.  Takes about 30 seconds to run.  I'll probably deprecate it after the edge transport server is built but in the mean time it works just dapper...


-----Original Message-----
From: MailScanner [mailto:mailscanner-bounces at] On Behalf Of Antony Stone
Sent: Tuesday, August 11, 2015 12:50 PM
To: MailScanner Discussion
Subject: Re: MS Gateway for Exchange 2013 - Any LDAP documentation?

On Tuesday 11 August 2015 at 22:40:51, Jerry Benton wrote:

> I am sure it can be done with sendmail. I am also sure Exchange 2013 
> has this setting. I have not spun up Exchange 2013 in the lab yet, so 
> I can’t give you exact instructions.

I'm absolutely no expert on MS Exchange, but is it possible that at least points you in the right direction?


> > On Aug 11, 2015, at 4:33 PM, Tracy Greggs wrote:
> > 
> > Thanks for the info Jerry.  My installation is with Sendmail and not 
> > postfix.  Your video is great but it is for Exchange 2010.  The 
> > Exchange
> > 2013 Admin Center does not have the applicable section to reject 
> > messages to users that do not exist.
> > 
> > Maybe my head is in the wrong place.
> > 
> > Does anyone on this list have a Mailscanner/Sendmail gateway in 
> > production use with Exchange 2013?  If so, how are you doing 
> > recipient verification from the MS gateway?
> > 
> > It’s not that I am 100% unwilling to go the postfix route, but I 
> > have been using Sendmail for 20 years and hate to change now.  It 
> > has always just worked flawlessly even in the MS gateway 
> > configuration with Exchange 2010 and milter-ahead to perform the call ahead.
> > 
> > The quick fix for me is to use Exchange 2010 for this installation 
> > but I would like to be able to get this working.
> > 
> > Again, maybe my head is in my arse!
> > 
> > Thanks,
> > Tracy Greggs

What do you get when you cross a joke with a rhetorical question?

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