Many office printers, scanners, accounting and other applications send email through Microsoft 365 with a simple user name and password (SMTP AUTH with Basic authentication). Microsoft is phasing this method out. If you do nothing, scanned documents and automatic emails may stop going out after the New Year.
Key dates
- Until the end of December 2026 – nothing changes, SMTP AUTH with a password works as before.
- At the end of December 2026 – SMTP AUTH with Basic authentication will be disabled by default for existing Microsoft 365 tenants. The administrator will still be able to turn it back on.
- For new Microsoft 365 tenants created after December 2026, this method will not be available by default.
- In the second half of 2027 Microsoft will announce the final date when Basic authentication for SMTP AUTH is removed for good.
What is affected
All devices and applications that connect to smtp.office365.com (port 587 or 25) with a mailbox password: multifunction printers with “scan to email”, accounting and warehouse software, website contact forms, monitoring systems and various scripts. Applications that support modern authentication (OAuth) are not affected.
What to check now
- In the Exchange admin center open the “SMTP AUTH clients submission report”: the “Authentication Protocol” column shows who still connects with Basic authentication and who uses OAuth.
- Make a list of all sending devices and applications: where they are, which mailbox they send from and whether the vendor supports OAuth.
- Update printer firmware and applications – newer versions often already support OAuth.
What are the alternatives
- OAuth – the best option if the device or application supports it: mail is sent through the same smtp.office365.com, just without a password.
- SMTP relay via a connector – the device sends to your MX address on port 25, and Microsoft 365 recognises it by a static public IP address or a TLS certificate. No licensed mailbox is needed, and mail can also go to external recipients.
- High Volume Email – a Microsoft 365 service for mail to recipients inside your own organisation only (for example, scanned documents for employees).
- Azure Communication Services Email – a cloud service for mail to both internal and external recipients when an application sends many automatic emails.
Temporarily the administrator will be able to turn Basic authentication back on, but this only postpones the problem: the final date will be announced in 2027, so it is worth planning the move now.
For partners
This is a good opportunity to contact customers who use Microsoft 365: check their sending devices together, and if you change the email setup, do not forget about archiving. In the partner zone you will find your prices, and for larger projects we prepare an individual offer within one business day.
Microsoft is retiring EWS: what it means for email archiving
Become a partner and see your prices
Business enquiry – an offer within 1 business day
Sources: Microsoft 365 Message Center post MC786329 (updated 27 January 2026), Microsoft Learn: How to set up a multifunction device or application to send email using Microsoft 365.