At 05:56 AM 7/1/2011, you wrote: >Hi to all, >i describe my scenarious and i'd like any suggest to resolve/limit the problem. > >Some user, in my University, reply to phishing email and give username and >password of your email account; then the malicious send spam email up to we >block account, but our server often will list in blacklist. > >There is a way to limit this problem? If i enable smtp-auth can i limit sent >email in timestamp?Any other suggestion?
I fixed this very bad problem we had with postfwd rate-limiting on our outbound gateway. I harvested from past outbound logs our legit senders of volume mail and except them from rate limiting. All other senders that exceed the rate limit get HOLD. fixed or problem. We have not been able to stop all phishing inbound (postfix/IMGate + clam + 3rd party sigs on MX, then barracuda for content-scanning), but even there, postfwd inbound rate limiting stops much of the phishing that comes in bunches of many 10s or 100s. Len >Thnaks in advance > >Antonio > >
