Re: validating from

On Sat, 2 Jun 2012, Matt Simerson wrote:

> Is it a good idea to validate that the MAIL FROM address is the same as 
> the From: header in the message?
> 
> What exceptions need to be made, if any?
> 
> What problems might I encounter if I were to do this?

For starters, you would penalise this message, and perhaps not see it.

> If the To header exists, shouldn't that also be validated against RCPT TO? 

Also wouldn't work well for mailing list messages.