>However, BTW a surprising number of legitimate sites, including >Gmail, have not been trying the lower-priority MX at all. Gmail >clients also tend to pass off to another host for second and >subsequent attempts, always and only on the primary MX IP address.
I don't see how Gmail will work, at times using this method as is. Gmail often sends the follow up second email from another mail server IP from my experience. So, how will this work with the deep tests mode of postscreen? I would think some mail will end up bouncing. What else can happen when the follow up comes from a different ip? >The greatest value I am seeing in postscreen is the DNSBL scoring >feature. We're able to use much more aggressive DNSBLs this way. >It's not unusual to see 3 of these in agreement on spammer hosts >which are staying below Spamhaus/Barracuda radar. Definitely!
