> If it's possible to throttle based on MX record for a domain, I'd really > appreciate your help.
I do it with the iptables packet filter (I'm on Linux, but I suspect there are similar packages on other systems). I shuttle incoming packets of the different protocols to individual chains, then use the 'recent' module to do rate limiting on the that protocol. It works pretty well. Sometimes somebody gets a little 'trigger happy' checking email or something. But if you like them, their IP (or their ISP) can just be whitelisted. If you're talking about outgoing traffic, the same thing could be done. -- Glenn English
