How to allow outgoing mail without relaying ?

How to allow outgoing mail without relaying ?

Post by Stuart Macki » Thu, 21 Nov 2002 22:01:13



I'm a little confused on something.  I belive I had accidentally allowed
relaying on my server for a few days becuase of a configuration change :(
Now resolved but I've had to enable SMTP authentication.  My E2k Server
receives mail for a number of domains (through port 25) as well as sending
emails for internal users.  Currently the Outoging SMTP connector is
configured with an Address space of * and has 'Allow messages to be relayed
to these domains unticked' (This is the setting I had enabled, stupid I
know).  In the Default SMTP Virtual Server I have set Relay to 'Only the
list below' which is empty, and enabled 'Allow all computers that
authenticate to relay'.  But what I then found was that if I sent an email
to an external domain (ie. not one of my own ones) I got the email returned
to the user stating relaying not allowed.  In Outlook I've temparily altered
the setting so that it Authenticated on sending the mail but this seems a
little overboard for what we're doing.  I recently reinstalled the server
and on the previous install I didn't have to enable SMTP authentication for
users and the server wasn't an open relay so I must have a setting wrong but
I can't work out what.

If I want to keep the server secure from relaying from externally but allow
internal users to send outgoing mail through the Virutal server what
setting(s) have to be altered to allow for this ?  Ideally I would like to
avoid the extra overhead of SMTP authentication and similarly not have to
specific internal IP's addresses on the 'Select which computers may relay
through this server' becuase if someone could gain remote access to one of
the workstations then they will be able to relay etc.  If I need to have
SMTP authentication then fair enough but I'm sure I didn't have that before
?

Thanks for any help,
Stuart.