we are looking for an additional method to avoid spam mail.
Blacklists (are already set) only help when a “bad” server sends mail, anti-relaying does not help when a message is sent to my own internet domain.
so the server accepts the mail, then sees that there is no such user in the address book and tries to send back the message.
this is what causes a lot of traffic (if the sender was an infected user with existing address) and additionaly a lot of sending attempts and dead mail with all the non-existing addresses.
so for that case we are looking for a functionality
to enforce the server FIRST to see if the adressee exists in his directory before accepting a mail or if not possible
*simply to turn off that notifications, the sending message back.
for the first possibility I wonder if the
"SMTP inbound controls, the item “Allow messages intended only for the following internet addresses”
is helpful, if I add a group with all users.
I don’t know if the server goes through it BEFOER oder AFTER accepting the message.
or is there a better way?
is there a way to switch off the the Router functionality of generating a failure message to the sender?
Care to disclose your relationship with Mailfrontier? I’m sure the solution’s good, but you can create bad feeling in a forum like this when you create umpteen thread responses extolling the virtues of a particular product.
Subject: Agreed - best thing is to be honest about it
If your solution solves the problem, it’s allright to mention it, but please be open about it being your own product. Ben Langhinrichs for instance usually refers to his product as “our Midas…”.
thanks, this looks good, but help says:"If all lookups complete successfully and no matching user name is found, the SMTP server returns a 550 permanent failure response indicating that the user is unknown. For example:
yes, it really checks before accepting the message. eg. the server rejects an invalid recipient by returning a status 550 and waits for the next recipient, if that one is valid then the message will be accepted (for all valid users only), if all users are invalid then the message will not be accepted at all so there will be nothing to go dead.
check out Mailfrontier’s Enterprise Mail Gateway solution. It blocks spam, relaying, directory harvest attacks and more and it has a great way to deal with false positives and almost no IT adminstration.