Brother scan to email with Office 365 after Basic auth ends

Brother publishes an OAuth 2.0 support statement. Many recent models support Microsoft OAuth out of the box or after a firmware update, and models not on the list don't support it. Those can still scan to email through a local relay.

What changes in December 2026

Microsoft's updated timeline (Exchange Team blog, January 27, 2026) says that at the end of December 2026, Basic authentication for SMTP AUTH is disabled by default in existing Exchange Online tenants. Admins can still turn it back on for the tenant or for single mailboxes. Tenants created after that date won't have it at all, and Microsoft will announce the final removal date in the second half of 2027.

Many Brother devices are set up with smtp.office365.com, port 587, STARTTLS and a mailbox username and password. That's Basic auth. When it's turned off, scans fail at the send step. The device log or the SMTP conversation usually shows a 535 5.7.139 error.

Option 1: native OAuth 2.0 on current Brother firmware

Brother's OAuth 2.0 Authentication Support Statement says: "To continue using these features in Microsoft Exchange Online (if your machine supports OAuth 2.0 authentication), you must update the firmware to the version that supports this authentication and configure the OAuth 2.0 authentication settings." Its product list is split into models that already support OAuth, such as some MFC-J inkjets and the HL-L2405W/L2460DW/L2865DW and MFC-L2760DW, and models that need a firmware update, which covers many mono and color lasers and the ADS scanners. Brother's advice for products not on the list is to "use an alternative email service (for example, Gmail)."

Brother's Exchange Online FAQ describes the setup. In Web Based Management, go to Network > Network > Protocol, click Third party (OAuth2), then Outlook, and enter the mailbox address. Note the displayed code, click Sign in, and finish at Microsoft. You're then sent back to the POP3/IMAP4/SMTP Client page.

Where the SMTP settings live in Web Based Management

Newer models: Network > Network > Protocol, then the SMTP Client settings (Brother FAQ). Older models such as the MFC-8510DN: Network > Protocol > Advanced Setting (Brother FAQ). There you'll find SMTP Server Address, SMTP Port, SMTP Server Authentication Method, SMTP-AUTH Account Name/Password and SMTP over SSL/TLS. If your model doesn't match either, check its manual.

Option 2: point the device at a local relay

If a device can't do OAuth, if the OAuth token keeps expiring, or if you run a mixed fleet and want one way to set everything up, point the device at a relay on your LAN. The device then sends plain SMTP to the relay, and the relay does the Microsoft 365 authentication. ScanRelay sends through Microsoft Graph as one mailbox you choose, so messages reach internal and external recipients, land in Sent Items, and need no DNS or SPF changes.

Device field	Value when pointing at ScanRelay
SMTP server / host	The relay's LAN IP or DNS name (for example `10.0.20.5`), not `smtp.office365.com`
Port	`25`, or whichever host port you mapped to the container
SSL/TLS or STARTTLS	Off, unless you gave the relay a certificate (`SCANRELAY_TLS_CERT`). If you did, use STARTTLS
SMTP authentication	None, if the device's IP is in `SCANRELAY_ALLOW_IPS`. Otherwise the per-device login from `SCANRELAY_USERS`
From / device email address	Anything sensible. The relay rewrites From to your sending mailbox and keeps the device address as Reply-To

On a Brother, set SMTP Server Address to the relay and SMTP Port to 25. Set SMTP Server Authentication Method to None (allowlisted IP) or SMTP-AUTH with the relay login, and set SMTP over SSL/TLS to None, or STARTTLS if the relay has a certificate. Also make sure the SMTP Client protocol is enabled under Protocol.

Deploy the relay (Docker or LXC) and connect it to one sending mailbox. The README has the app registration and the RBAC for Applications commands.
Add the device's IP to SCANRELAY_ALLOW_IPS, or give it its own login.
Change only the SMTP host, port, TLS and authentication fields on the device, as shown in the table above.
Send a test scan to an internal and an external address, then check Sent Items on the sending mailbox.

Which option should you use?

Current model with OAuth firmware available: use native OAuth. It's supported by the vendor and needs no extra box. Plan for the case where a token has to be re-authorized, for example after a password reset, a Conditional Access change or a long outage.
Older model with no OAuth firmware: a relay (ScanRelay, or a Microsoft connector) is the realistic way to keep scan-to-email going. Scan to folder or SMB is another option.
Mixed fleet or an MSP managing many sites: a relay per site means one set of settings for every brand, and one place to watch delivery logs and secret expiry.

Comparing every approach, including HVE, direct send and third-party senders? Read the hub guide.

Keep older scanners sending, without a third-party mail service

ScanRelay takes plain SMTP from devices on your LAN and sends it as your own mailbox through Microsoft Graph with OAuth. It's open source and self-hostable. The hosted relay and MSP dashboard are in beta from October 2026.

Join the beta View on GitHub