Thank you for the postfwd link. Not sure why I didn't find this during my research. I guess I didn't have the right Google keywords. :)
On Wed, Feb 4, 2015 at 8:41 AM, Wietse Venema <wie...@porcupine.org> wrote: > Dave Jones: > > I need to be able to relay outbound for this customer of ours as a > service > > we provide and I need to be able to block compromised accounts which I > have > > been successful at for years until this new spam technique showed up a > few > > weeks ago. > > I do have a way to detect this Bcc sending _after the fact_ and put in a > > DISCARD for the sending address to stop the spam but some have already > > gotten out. When Bcc'ing 300 at a time, even a few getting out will > create > > a lot of damage to our IP's reputation. > > Use postfwd, set a rule that triggers with too many recipients > per SASL login. http://www.postfwd.org/ > > Wietse >
