Fix Office 365 SMTP Authentication Errors on a Scan-to-Email Printer
Question details
The user needs a Fuj Xerox multifunction printer to authenticate with Office 365 for scan-to-email.
- Product
- Microsoft 365 Exchange Online and Fuj Xerox multifunction printer
- Device & OS
- not provided
- Scenario
- The printer uses SMTP client submission to send scanned documents through an Office 365 mailbox.
- Observed behavior
- Authentication fails with smtp.office365.com on port 587 using STARTTLS, despite correct mailbox credentials; sending through Gmail works.
Sign in to the Microsoft 365 admin center with an account that can manage the printer mailbox. Check the printer model's documentation or web interface to confirm its TLS and SMTP authentication capabilities.
Enable Authenticated SMTP for the printer mailbox
Use this solution when SMTP AUTH appears enabled in PowerShell but the printer still cannot authenticate.
In the reported case, the Microsoft 365 admin center showed Authenticated SMTP as disabled even though PowerShell showed it as enabled. Enabling it in the admin center and allowing time for synchronization resolved the mismatch.
In the Microsoft 365 admin center, go to Users > Active users and select the mailbox used by the printer.
Open the Mail tab, select Manage email apps, check Authenticated SMTP, and save the changes.
Wait for the change to synchronize, then reopen Manage email apps to confirm the setting remains enabled. If you use Exchange Online PowerShell, check the mailbox setting with Get-CASMailbox -Identity <mailbox> | Format-List SmtpClientAuthenticationDisabled.
In the printer's email or SMTP settings, enter smtp.office365.com, port 587, STARTTLS, and the printer mailbox credentials. Confirm that the printer supports TLS 1.2 or later, then send a test scan.
If the test still fails, check your Microsoft 365 security policies and current Exchange Online SMTP AUTH requirements. Confirm that the printer supports an authentication method permitted by your tenant.
Use Exchange Online direct send for internal recipients
Use direct send as an alternative when the printer cannot use SMTP AUTH and only needs to send to recipients in your Microsoft 365 organization.
Work with Office Documents in WPS Office
WPS Office is a free, lightweight alternative with a familiar interface and support for Microsoft Office formats, making it easy to move your document work. It does not change Exchange Online or printer authentication settings.
Frequently Asked Questions
Where do I enable SMTP AUTH for the printer mailbox?
In the Microsoft 365 admin center, go to Users > Active users, select the mailbox, and open Mail > Manage email apps. Enable Authenticated SMTP and save.
Why does PowerShell show SMTP AUTH enabled when the printer cannot sign in?
A provisioning or synchronization mismatch can cause the admin center and PowerShell to show different states. Check the mailbox's Authenticated SMTP setting in the admin center, save it if needed, and allow time for synchronization.
Does the printer need TLS 1.2 for Office 365 SMTP submission?
Yes. Check the printer's SMTP or security settings and manufacturer documentation to confirm support for TLS 1.2 or later. SMTP client submission uses smtp.office365.com on port 587 with STARTTLS.
What can I use if my printer does not support SMTP AUTH?
For mail to your own Microsoft 365 organization, configure direct send using your domain's MX endpoint on port 25. For external recipients, consider SMTP relay with an Exchange Online connector.
Why does Gmail work while Office 365 authentication fails?
The services can have different TLS and authentication requirements. Check the Office 365 mailbox's Authenticated SMTP setting, tenant policies, and the printer's supported authentication methods.
