Ref 1) How do I turn off SMPT relay for hosts outside our domain? December
02, 1998 1:30 AM, Michael J. Carter
2) Spamer forwarding thru our system. Help, November 30, 1998 5:47 PM, Ray
Still looking for a complete fix for the relay problem. We are Exchange ver
5.5 pre sp1. We identified a spamer routing thru us. We reconfigured in
admin to configuration/connections/IMS/delivery restrictions/ do not
reroute incoming SMTP mail. No significant problems, and no spam
rerounting. The guy may have just given up for a while. After added
research we become concerned we may still be vulnerable. Tried the test in
http://maps.vix.com/tsi/ and it report we may be vulnerable. We elected to
try relay restrictions by regestry changes. Best choice appeared to be the
one that ' Specifies hosts that can relay messages through your server'
(RelayAllowList, REG_MULTI_SZ) We elected to leave the value blank so no
one was relayed. This closed the hole. If you tried, you got a 550
Relaying is prohibited. But we found it also stopped all Internet in to our
users. I am looking at the Service Pack 1 htm readme. It appears SP1 just
automates these regestry changes. My new questions are:
1) If you did SP1, choose host and clients that can route, and then did not
specify anyone would it also stop Internet mail to internal users?
2) Will it pass the relay test?
3) Could I just specify my exchange server to get the internal users
4) Any better suggestions?