Common IMAP/SMTP Settings:
- Gmail: imap.gmail.com:993, smtp.gmail.com:587
- Outlook: outlook.office365.com:993, smtp.office365.com:587
- Yahoo: imap.mail.yahoo.com:993, smtp.mail.yahoo.com:587
Note: You may need to enable "Less secure app access" or use app-specific passwords for some providers.