> A) how does it help prevent spam (I can very well send you mail faking > [EMAIL PROTECTED])? In fact, most spammers not just uses a legitimate > domain name, they even exploit the open proxies to fake as if the mail is > coming from that domain. To me it looks like a needless overhead for your > smtp server.
You are right; it won't block all spam with just this simple check. (Ghane lives in Singapore, where spams are blocked by themselves, simply because the Singapore government has made them illegal; they just wither away and die for lack of nourishment. This is not applicable to you or me.) However, it does block a part of the spam. There are now more involved checks being done by receiving MTAs, like sender address "callback", which are more effective. > B) why do you check for "A" records? Why is just checking for "MX" records > not enough? (if we expect that somehow "legitimizes" the user. Because the SMTP standard says that it's okay for a domain to just have A records and not MX records, if it wants to receive email. Therefore, all SMTP MTAs have to check "A" records too. Shuvam _______________________________________________ ilugd mailing list [EMAIL PROTECTED] http://frodo.hserus.net/mailman/listinfo/ilugd
