Fix smtp.office365.com Error 016-781 on Xerox Printers
Question details
Users need to resolve an issue where Xerox multifunction printers fail to send scanned PDF attachments via Microsoft 365, returning error code 016-781.
- Product
- Microsoft 365
- Device & OS
- not provided
- Scenario
- Scanning documents to email and sending PDF attachments using the smtp.office365.com server.
- Observed behavior
- The printer stops sending emails and attachments, and the machine displays error 016-781.
Ensure you have network access to the Xerox printer's web interface (CentreWare Internet Services) and that you know your organization's Microsoft 365 domain MX record.
Configure Printer to Use Domain MX Record
Changing the SMTP server address to your organization's direct MX record bypasses the SMTP AUTH requirement that typically causes error 016-781.
Microsoft 365 has stringent authentication requirements for SMTP client submission via smtp.office365.com. When older hardware like certain Xerox printers cannot meet these authentication standards, routing emails directly through the MX record using Direct Send on port 25 without SMTP AUTH is the most reliable workaround.
Find your Xerox printer's IP address and enter it into a web browser to access the CentreWare Internet Services portal. Log in as an administrator.
Go to Properties > Connectivity > Protocols > SMTP Server to access the outgoing email configuration.
Replace 'smtp.office365.com' with your domain's specific MX record (for example, 'yourdomain-com.mail.protection.outlook.com').
Change the outgoing port to 25 and ensure that SMTP Authentication (SMTP AUTH) is completely disabled.
Apply the new settings, restart the printer if prompted, and perform a test scan to email to confirm the PDF attachment is successfully delivered.
Escalate to Microsoft 365 and Xerox Support
If updating the SMTP settings to use the MX record does not resolve the scanning issue, official support intervention is required.
Looking for a hassle-free alternative to Microsoft 365?
If managing Microsoft 365 configurations and strict authentication protocols is becoming too complex for your organization, consider switching to WPS Office. It provides a comprehensive, highly compatible office suite for all your document and PDF needs without the heavy subscription costs.
- 1. Download the software: Visit the official WPS Office website to download the free installation package for your operating system.
- 2. Install WPS Office: Run the downloaded installer and follow the simple on-screen instructions to set up the application.
- 3. Manage your files: Easily open, edit, and organize your Office documents and scanned PDFs without complex server configurations.
Frequently Asked Questions
What causes error 016-781 on Xerox printers using Microsoft 365?
This error typically occurs when the printer fails to authenticate with the Microsoft 365 SMTP server. It is often triggered by Microsoft disabling basic authentication, or incorrect port and SSL/TLS configurations for smtp.office365.com.
How do I find my Microsoft 365 MX record for the printer setup?
Administrators can locate the MX record by logging into the Microsoft 365 admin center, navigating to Settings, selecting Domains, clicking on the active domain, and viewing the DNS records.
Can I still use port 587 for Xerox scan to email?
Port 587 requires STARTTLS and successful SMTP AUTH. If your Microsoft 365 tenant blocks basic authentication or your printer doesn't support the required TLS version, port 587 will fail, and you must use Direct Send via port 25 with your MX record.
