Trying to get them fired by sending things via their email will be tricky, since they can pretty plausibly claim they didn't send it. IT can pull logs, and even if they can't be used to identity you, they can demonstrate someone other than your boss sent the email. So, a mass email from their account won't do much. Especially if it's something out of character for them to send
Here's an alternative: If you have access to their communication and can find something bigoted they sent in private, you can forward that message out to the whole department. It was a real email and records will show they sent it, even if foul play was involved in exposing it.
Trying to get them fired by sending things via their email will be tricky, since they can pretty plausibly claim they didn't send it. IT can pull logs, and even if they can't be used to identity you, they can demonstrate someone other than your boss sent the email. So, a mass email from their account won't do much. Especially if it's something out of character for them to send
Here's an alternative: If you have access to their communication and can find something bigoted they sent in private, you can forward that message out to the whole department. It was a real email and records will show they sent it, even if foul play was involved in exposing it.