ERROR: 'Outlook doesn't recognize one or more names' in event viewer

What to do if you see this error when emailing documents from Sage 50 Accounts or Sage 50 Payroll.

Since a recent Microsoft Outlook update on 21 April 2026, some users are unable to send emails with various messages including:

• Error with the address: Unknown Error
• Generic COM Error
• Unable to communicate with Microsoft Outlook
• The report has failed to output to email

This error only occurs when you send emails immediately from outlook.  

To check if the Microsoft update caused your error

1. Type Event viewer in the search box on your taskbar.
2. Click the Event Viewer app, then maximise the window of the app.
3. Click Windows Logs in the list to the left, then select Application.
4. Check the section headed Application for any errors where the Source is Sage Report Designer.
5. Select an error to view its details in the General tab below.
6. Check for the message 'Outlook doesn't recognize one or more names'. 

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Workaround

If you're unable to do the above, change your settings to save emails to your mailbox and send from there. 

1. Go to Settings, then click Email Defaults.
2. In the Email Program dropdown, click Microsoft Outlook.
3. Select the tab for the items you send via email. 
4. In Sending Options, choose Save To Mailbox.
5. Click Apply and select the checkbox for each layout to apply the email settings to.
6. Select OK then OK.

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