[Greylist-users] SMTP/AUTH before greylist problem

[William Blunn]

Dave Warren wrote:

> No -- The problem is that *every single time* they configure their 
> mail client they have to change the port from 25 to 587.  This results 
> in a support cost every time a user needs their client configured.
>
> My instructions have used 587 since the day I added support on my mail 
> server, but most people still use 25 because they simply don't bother 
> to go into the Advanced options to configure anything even if the 
> instructions tell them to do so.

You could block TCP connections to port 25 for hosts inside your 
network. That would force people to configure correctly from day one.

Better yet, you could put in a networking rule so that TCP connections 
to port 25 originating inside your network are redirected to port 587?

Under netfilter that ought to be something like:

  iptables -t nat -A PREROUTING -s $mynetwork -p tcp --dport smtp  -j 
REDIRECT --to-port 587

Bill
-- 
The contents of this e-mail and any attachments are confidential and may 
be legally privileged.  If you have received this e-mail and you are not 
a named addressee, please inform us as soon as possible on 
+44 118 901 2999 and then delete the e-mail from your system.  If you 
are not a named addressee you must not copy, use, disclose, distribute, 
print or rely on this e-mail.  Any views expressed in this e-mail or any 
attachments may not necessarily reflect those of Tao's management.  
Although we routinely screen for viruses, addressees should scan this 
e-mail and any attachments for viruses.  Tao makes no representation or 
warranty as to the absence of viruses in this e-mail or any attachments.  
Please note that for the protection of our business, we may monitor and 
read e-mails sent to and from our server(s).