Quick answer
Use secure IMAP and authenticated SMTP for an existing hosted mailbox. The old video's suggestion that port 587 is an unencrypted default should not be followed.
Applies to
Historical reference for Outlook 2016 while moving to a supported mail client. Microsoft ended Office 2016 support on October 14, 2025. Classic Outlook, new Outlook and other clients use different menus. Preserve local-only mail and contacts before migration.
Steps
- Preserve local-only mail and obtain the exact provider settings, including the full mailbox username.
- In the older interface, File > Add Account > Advanced Options offers manual setup. Select IMAP; a supported replacement client may use a different setup flow.
- Use the provider's incoming TLS settings, commonly IMAP 993, and authenticated SMTP, commonly 465 with implicit TLS or 587 with STARTTLS. Verify the server hostname matches its certificate.
Check the result
Send and receive controlled messages, check Sent placement and confirm expected folder synchronization.
Troubleshooting and support
For failed sign-in, check the mailbox password and full address. For certificate errors, correct the hostname/certificate instead of disabling validation.
If the problem continues, contact support from the account that owns the service. Include the domain, exact error, time and time zone, tool name, and a redacted screenshot. Keep passwords, private keys, cookies and private message content out of the ticket.
Video tutorial
The original video is preserved. Its interface or product version may differ from the written guidance above.
Related help
- Find the correct secure IMAP and SMTP settings for your mailbox
- Use webmail to separate a mailbox problem from a device problem
Official references
Written content reviewed November 1, 2026. Menu availability depends on the product version, permissions and service.
