Is it possible to verify "from:" header addresses?

[Adam Moffett]

We're doing sender verification for our local domains, so a message sent 
from "f...@plexicomm.net" gets rejected.  A message with an envelope 
sender of "va...@spammer.com" with a from: header of 
"f...@plexicomm.net" gets accepted.  Is there a way to enable 
verification on "from:" header addresses?

I scanned through the docs for options with the word "verify" in their 
name, and didn't see anything that looked promising.