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O365

Abigail Mundy, Product Marketing Specialist

Office 365 Is Retiring Basic SMTP—Here’s Your 3‑Step Plan Before March 2026

Last updated June 23, 2025

Step 1: Understand the Change

Remember when one key unlocked every door in the building? Handy—until someone made a copy. That’s essentially how Basic SMTP Authentication works, and Microsoft is taking that universal key away on March 1st, 2026. After that date, any printer, scanner, or line‑of‑business app that still relies on a stored username and password to send email through Office 365 will simply stop, often without an obvious error message. 

Typical failure code: 550 5.7.30 Basic authentication is not supported for Client Submission

Microsoft’s goal is simple: shut down a decades‑old protocol that can’t enforce multi‑factor authentication (MFA) and is prone to brute‑force attacks.

Step 2: Meet OAuth 2.0 & Choose Your Path

Instead of keeping passwords on devices, OAuth issues short‑lived, encrypted tokens. Tokens can be scoped to specific tasks (like “send mail only”) and revoked at any time. That means no more password vaults on printers and no more panic when an employee’s credentials change.

Why tokens win:

  • No stored passwords → fewer credential‑theft risks.
  • MFA‑ready → aligns with today’s security posture.
  • Granular permissions → devices get only the access they need.

Path 1: Generate & use OAuth tokens

Best for: newer devices that already support OAuth (often after a firmware update).

Implementation steps

  1. Verify the device’s firmware level.
  2. Register the device in Azure AD.
  3. Generate an OAuth token.
  4. Enter the token and tenant details on the device.
    Vendor Guides:
    Ricoh
    Canon
    Kyocera
    HP
    Toshiba
    Lexmark

Path 2: Stay fully inside Microsoft 365

Best for: workloads that can’t handle tokens but still need to send mail.

Options:

  • High Volume Email for Microsoft 365 – internal recipients only
  • Azure Communication Services Email – internal & external recipients
  • On‑prem Exchange hybrid – create a Receive connector on your local server and relay through it

Path 3: Use a third‑party SMTP relay

Best for: legacy gear with no firmware path.

These services generally still allow using user/password combinations but have additional costs and deployment considerations.

Step 3: Execute & Verify

  1. Audit every device and application that sends mail through SMTP AUTH.
  2. Tag each one as OAuth‑capable, Microsoft relay, or third‑party relay.
  3. Update firmware or schedule hardware refreshes where needed.
  4. Document token creation and renewal procedures.
  5. Test and monitor for the 550 5.7.30 error.

How Applied Innovation Can Help

  • Firmware upgrades: Customers with an active Maintenance Agreement can open a Service Call and we’ll update supported devices.
  • Token hand‑off: Once your IT team generates the OAuth credentials, our networking techs will populate them on your printers or copiers.
  • Planning support: Need a roadmap? We’ll help you weigh Microsoft relay vs. third‑party services and outline a phased rollout.

What we don’t do: For security and compliance, Applied Innovation cannot create OAuth tokens on your behalf or configure third‑party SMTP relays. We’re happy to collaborate with your IT pros every step of the way.

Useful Resources

Bottom Line

Bottom line: March 2026 will be here before you know it. Start auditing today, lock in your path, and give your scanners and apps the secure future they deserve. Need a hand? Let’s talk.