Whitelisting

[toolshed1]

Hi,

I have a vendor that is sending us a good amount of email. I usually use HAT to apply diff. throttling policy however in the case of this vendor when I look at logs they are sending from a lot of diff IPs and DSN hostnames (looks like they are using outlook.com prob for email filtering). Their Envelope sender domain doesn't match their DNS hostname. 

What would be the best way for me to whitelist them

[toolshed1]

Typically I put blocks through content filtering when phishing or spam already made it through. Is there a more of a pro-active way of doing that. Usually I have a sample of a message from one of the users.