What changes for Lexmark devices
Microsoft's notice MC786329: “End of December 2026: SMTP AUTH Basic Authentication will be disabled by default for existing tenants.” It applies to any device that signs in to Microsoft 365 with a username and password, whatever the brand. Admins can still turn it back on for now. Microsoft will announce the final removal date in the second half of 2027.
What Lexmark says about Microsoft 365
For Microsoft 365 OAuth 2.0 Authentication, you must register your printer to OAuth 2.0 Authentication.
Lexmark, Configuring the email SMTP settings (read October 30, 2026)
- “These settings apply to outlook.com and hotmail.com email domains and Microsoft 365 accounts.” (Source)
Where the scan-to-email settings are
In Lexmark's instructions the device's browser settings page is called Embedded Web Server (Source). Open it by typing the device's IP address into a browser on the same network, and sign in as the administrator.
The email settings, as Lexmark names them: Settings > Email (Source)
Turning on OAuth, in Lexmark's words
- Scroll down to the Set Up OAuth 2 for Email Server section, and then click Register. (Source)
- Setting up the SMTP settings using the email setup wizard is not applicable for OAuth 2.0 Authentication. (Source)
Whichever route you choose, you'll fill in the same handful of fields: the SMTP server, the port, the encryption, whether to sign in, and a username and password.
Your options on a Lexmark
1. OAuth, on models Lexmark lists
Microsoft recommends OAuth for devices that send through smtp.office365.com. The device keeps port 587 and TLS (TLS 1.2 or TLS 1.3) and signs in with Microsoft instead of a stored password. Follow Lexmark's steps on the page above.
2. CopierBridge, for devices that can't
Keep the device on a username and password. Turn on Authenticated SMTP for the mailbox it sends as (Microsoft's steps), connect that mailbox to CopierBridge once, add the device, and type these values into its scan-to-email settings:
- SMTP server
- smtp.copierbridge.com
- Port
- 587
- Encryption
- STARTTLS
- Authentication
- On (username and password)
- Username
- frontdesk-copier
- Password
- ••••••••••••••••
- From address
- scans@example.com
3. Microsoft's other routes
An SMTP relay connector (static IP, port 25), Direct Send or High Volume Email (both internal recipients only), or an on-premises Exchange relay. Each one is set out step by step in the full guide.
If scan to email stopped working
Read the message the Lexmark shows and look it up on Microsoft 365 SMTP errors, or work through scan to email not working.