If Hotmail is not working on Mac Mail, it could be due to incorrect settings, outdated credentials, or a server issue. Ensure you’ve entered the correct email address and password. Update your Mac Mail app and check your internet connection. Verify that IMAP/SMTP settings are accurate: IMAP server: imap-mail.outlook.com, SMTP server: smtp-mail.outlook.com. If the issue persists, try removing and re-adding the account or contact Microsoft support for further assistance.
Fixing SMTP Email Error 501 5.1.3: Address Formatting Issues and Solutions