Tech Q&A: Fixing a Mac that can't send e-mails with attachments

A conflict between Outlook and Big Sur could be preventing your computer from sending out emails. — 123rf.com

Q: Right after I upgraded my Mac to the Big Sur 11.3 operating system, I could no longer send e-mails with attachments using the Microsoft Outlook program. I get an error message that says "a secure connection cannot be established with the server smtp.comcast.net."

— Rick Bruzek, Santa Fe, NM.