Great solution Elliott, that should work.
I would also consider the simple solution of printing out both Company and Inferred Company fields in the email alert. This will give the sales reps more info, which is also interesting if someone provides an incorrect company name, but the inferred company is correct. Alternatively, if company is blank and inferred is Comcast or Roadrunner, the rep can see that this is inferred and therefore less reliable (and in this example, it probably is an ISP).