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.

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 CAN send a test message using Outlooks built in test feature. I can also send email from the command line using telnet to the ISP's mail server on port 25. This always works.

Here at work, we've got a single server doing email and file serving. It works just fine, but my job requires me to occasionally send out large .pdf attachments. Anything over around 3.2 MB gets ...