Walt needs to ensure that messages from a colleague in another organization are never incorrectly identified as spam. What should he do?

Walt should configure the colleague as a safe sender. A safe-sender setting tells the mail system to trust messages from that address or domain, reducing the chance they will be incorrectly sent to spam. A safe recipient applies to messages sent to a recipient, while a blocked sender does the opposite by marking a sender as unwanted.

AI-written and checked against the verified answer.