On Thu, Aug 6, 2009 at 8:39 AM, Charles Marcus<cmar...@media-brokers.com> wrote: > On 8/6/2009, Santiago Romero (srom...@servicom2000.com) wrote: >> By adding the following to my main.cf, I'll check RCPT TO addresses >> against primary MX, except when PRIMARY MX doesn't answer. In that case, >> I'll accept any destination for my relay_domains list, just like I was >> doing before adding those lines: >> >> address_verify_map = btree:/var/lib/postfix/verify >> address_verify_positive_refresh_time = 14d >> unverified_recipient_defer_code = 250 > > You are correct, but this is NOT the recommended way... > > Don't change the unverified_recipient_defer_code to 250... leave it at > its default 450. This way you will not be a backscatter source ever, and > the worst that will happen if their primary MX is down is some mail > might be delayed a little. >
Which is also exactly what would happen if they didn't pay this guy for a backup MX. He's looking for some way to think his service has value, and doesn't mind being a nuisance by backscattering so long as he can make a buck. lame. > Also, if I'm understanding the way this works correctly, you can also > use the address_verify_map parameter to cache hits (both negative and > positive), which will allow you to continue accepting mail for > recipients who are still in the cache even if the primary MX is down. > > http://postfix.mirrorspace.org/postconf.5.html#address_verify_map > > -- > > Best regards, > > Charles >
