On Mon, 28 Sep 2015 17:29:15 -0700 Dave Warren wrote:
> You might also want to see if you can avoid greylisting some big > senders. There is zero advantage in greylisting Google, Outlook.com, > Outlook 365, Yahoo, AOL, etc, as you know they're real mail servers > and you know they will retry. For senders that send a large amount of > good mail, content filtering is worthwhile, but greylisting won't do > anything but potentially delay legitimate traffic. That's not entirely true because there's scope for URIs and deep IP addresses to get listed during the delay, and Bayes to learn from spamtrap addresses.
