does imgate somehow talk to imail to verify an account is valid first
it can, with reject_unverified_sender (RAV receipient address verication), this works fine for smaller sites, and it works for Imail users tryig to send out through IMGAte. IMGate won't accept mail from IMail if IMGate's probe of the remote recipient's MX is not positive.
or does it just accept the email then attempt to send it and if unknown user, bounce it
This is not recommended, because a dictionary attack would quickly swampt Imail�s queue with (mostly undeliverable) mailer-daemon msgs to forged senders.
For larger sites, the list of mailbox users should be exported to IMGate, so only that mail is allowed. This allows IMGate to block dictionary attacks (as does RAV) + harvest the attacking IPs and Class Cs into blacklists, which are single-criteria reject lisst of very high reliability (the IPs put themselves in those blacklists by their own behavior agains that specific IMGate.)
Len
_____________________________________________________________________ http://MenAndMice.com/DNS-training: London; San Jose; Wash DC IMGate.MEIway.com: anti-spam gateway, effective on 1000's of sites, free
To Unsubscribe: http://www.ipswitch.com/support/mailing-lists.html List Archive: http://www.mail-archive.com/imail_forum%40list.ipswitch.com/ Knowledge Base/FAQ: http://www.ipswitch.com/support/IMail/
