For many IT teams, Microsoft 365 is where an old copier first runs into a modern identity problem. SMTP AUTH describes the submission method; OAuth describes how the sending identity can authenticate without handing a long-lived mailbox password to the device.
Why this matters
Older copiers often expect a username and password and have no concept of a browser-based OAuth consent flow.
OAuth uses access tokens that are scoped and time-limited instead of exposing the user's normal password.
Keep the copier simple
The copier is usually the hardest component to update and the least pleasant place to troubleshoot identity. Where possible, keep the device-side configuration limited to ordinary SMTP settings and move modern authentication, token refresh, policy, and detailed logging into a service designed to handle them.
Practical points to consider
- A relay can bridge the gap by accepting SMTP from the copier and using OAuth when it talks to Microsoft 365.
- The security benefit is not only stronger authentication; revocation and permission scope are easier to manage.
- Do not confuse SMTP AUTH with Basic authentication. SMTP AUTH can support modern authentication.
What a supportable setup looks like
A good Scan-to-Email design should be understandable months after it is installed. IT should know which device is sending, which cloud connection is being used, which destinations are permitted, and where to look when delivery fails.
That usually means using a dedicated or clearly owned sender identity, encrypted credentials or tokens, modern TLS on the cloud side, useful logs, and a documented reconnect process. It also means avoiding broad permissions simply because they are easier to configure.
Where CM Relay fits
CM Relay is designed as the compatibility and policy layer between copiers or other SMTP devices and modern cloud services. The copier can continue using a familiar SMTP workflow while CM Relay handles OAuth-based delivery, connection health, logging, and policy controls such as sender and destination restrictions.
That approach lets an organization modernize the email path without turning a copier replacement project into the only security option.
Further reading
- https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/authenticated-client-smtp-submission
- https://learn.microsoft.com/en-us/exchange/clients-and-mobile-in-exchange-online/deprecation-of-basic-authentication-exchange-online
Next step
If your organization is still relying on old SMTP credentials, inconsistent copier settings, or manual workarounds, start by documenting the current Scan-to-Email path. From there, you can decide which parts need to be modernized without disrupting the user experience.
https://cmrelay.com/features/ or https://cmrelay.com/contact/ to discuss your environment.