[K12OSN] Student email

Les Mikesell les at futuresource.com
Thu Dec 9 02:12:08 UTC 2004

On Wed, 2004-12-08 at 18:59, Jim Kronebusch wrote:

> Bottom line is Postfix gives you a ton of options for configuring who your 
> users can send to.  

One thing to check is when and how it rejects the bad addresses.  If you
have people running outlook on the internal LAN that are allowed to
receive outside email with other accounts you'll likely have viruses
spewing thousands of emails at anything that allows connections on
port 25.  With SME (up to verion 5.6 anyway), a dump smtp receiving
process accepts everything and queues it for delivery.  Then the
delivery process tries to return the ones that can't be delivered.
This becomes really ugly when the messages are coming in faster
than the return attempts work to the forged sender addresses. The
same applies if you allow internet access on port 25 and depend on
the mailer's handling to reject non-local users.  A really simple
solution would be to run on the main k12ltsp server with the
clients and webmail app configured to use (localhost) and
the smtp server configured to only accept there (the RH default).

  Les Mikesell
   les at futuresource.com

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