Brother MFC printers send scans by plain SMTP, and Microsoft 365 no longer accepts that directly. The fix is to point the printer at a relay on your network that does the modern authentication for it. These are the settings, in Web Based Management (the printer's web page). They apply to MFC and DCP business inkjet and laser MFPs; menu names differ a little between firmware generations.
Open Network → Network → Protocol → SMTP → Advanced Settings (newer models: E-mail / Fax → E-mail Send → SMTP) and set:
| Field | Value |
|---|---|
| SMTP Server Address | the SMTP-365 appliance's IP address |
| SMTP Server Port | 2525 |
| Server Authentication Method | None |
| SSL/TLS | None |
| Verify Server Certificate | unchecked |
| Device E-mail Address | the scanner mailbox address |
Port. The port is on the same page.
Save, and restart the printer if it asks. Nothing else in the email setup needs to change: the address book, scan-to-me, scan-to-folder and fax forwarding are unaffected.
Use Send Test E-mail on the SMTP page, then a real scan from Scan → to E-mail Server. Within a few seconds it should arrive from the scanner mailbox. On the appliance, the Status page shows the job as delivered. To scan to SharePoint, add a route and put its address in the printer's address book.
| What you see | Likely cause | Fix |
|---|---|---|
| Connection failed / cannot connect to server | Wrong relay address or port, or the device's subnet is not in the relay's allowed sources | Check the address and port; on the appliance, Settings → Devices, add the device's subnet |
| 554 5.7.1 Relaying denied (or the connection closes at once) | The device's IP is not among the appliance's devices | Add the address or subnet under Settings → Devices on the appliance |
| Authentication or certificate error on the device | Authentication or TLS is still switched on in the device | Set authentication to none/off and SSL/TLS to off; the relay is plain SMTP on the LAN |
| Device says sent, nothing arrives | Delivery to Microsoft 365 failed and the job is held or failed | Open the appliance's Status page: held and failed jobs show the reason and can be re-queued |
| Arrives, but from the wrong address | The device's own From address is being used | Turn on the sender override on the appliance so every message is sent from the scanner mailbox |
The printer goes back to plain SMTP on the LAN, with no mailbox password stored in it and no TLS to fail on old firmware. The appliance holds one application identity in your tenant with at most three permissions (Mail.Send, Sites.Selected, and Mail.ReadWrite for large attachments; apply the Exchange scope the setup page gives you to limit the mail permissions to your scanner mailbox), sends every scan as your scanner mailbox, and delivers through Microsoft Graph. The same appliance serves every other Brother device on the site, every other brand, and the UPS, NAS and servers that also need to send email. Background: what Microsoft changed.
Updated 2026-10-10. Menu names and screens vary between models and firmware versions; if yours differs, look for the same fields under the device's email, SMTP or notification settings. Corrections welcome at helpdesk@smtp-365.com.