Topic: Email Sender verification

[SSBN]

Email Sender verification

I have seen a few products that can do this like the astaro firewall. From what I understand when someone sends me email  from say david@ispjunk.com the software will whois or ping the ispjunk.com domain. If it replies I get the mail. If it doesn’t the mail is dropped.

Do any of you know if this is around for SME 6.0.1? I recall there is an RBL you can enter that will do this. If any of you are aware of one that will do that could you post it? Thanks. TMDA settings are not what I am looking for as they require the sender to verify the email.

This is for a front end for exchange so I can’t use Spamassassin as it forwards the mail before SA can look at it.

[NickR]

You can have this feature if you patch the qmail source & recompile.  The patch is available here:

http://js.hu/package/qmail/qmail-1.03-mfcheck.4.patch

Personally, I think it's a waste of time, but you did ask.  Here's what the author says:

"It checks envelope sender (MAIL FROM: domain address) in DNS. Warning: it is not intended to filter out spammers, just a precaution not to accept mails from knowningly illegal addresses, and you'll get a lot less double bounce messages. Besides, it conforms with RFC 2821, section 3.6. Many thanks to Salvatore Toribio to help find a nasty bug around bounce checks."