Sunny

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Recent migration to Cloud Office 365. Test to self - OK Test to external gmail address - OK Reply from that email ... Mail Delivery Subsystem &lt;mailer-daemon@googlemail.com&gt; 10:32 (41 minutes ago) to me Error Address not found Your message wasn't delivered to zzzzzz@zzz.com because the address couldn't be found or is unable to receive email. The response from the remote server was: 550 5.1.1 User unknown 
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Recent migration to Cloud Office 365.
Test to self - OK
Test to external gmail address - OK
Reply from that email ...
Mail Delivery Subsystem <mailer-daemon@googlemail.com>
10:32 (41 minutes ago)
to me
Error
Address not found
Your message wasn't delivered to zzzzzz@zzz.com because the address
couldn't be found or is unable to receive email.
The response from the remote server was:
550 5.1.1 User unknown

External gmail sent to one user with know good address &quot;550 5.1.1 User unknown&quot;  We recent migration to Cloud Office 365.

Office 365 is a group of software plus services subscriptions that provides productivity software and related services to its subscribers. Office 365 allows the use of Microsoft Office apps on Windows and OS X, provides storage space on Microsoft's cloud storage service OneDrive, and grants 60 Skype minutes per month. Office 365 includes e-mail and social networking services through hosted versions of Exchange Server, Skype for Business Server, SharePoint and Office Online, integration with Yammer, as well as access to the Office software. All of Office 365's components can be managed and configured through an online portal; users can be added manually, imported from a CSV file, or Office 365 can be set up for single sign-on with a local Active Directory using Active Directory Federation Services.

Microsoft 365

Microsoft Outlook is a personal information manager from Microsoft, available as a part of the Microsoft Office suite. Although often used mainly as an email application, it also includes a calendar, task manager, contact manager, note-taker, journal, and web browser.

External gmail sent to one user with know good address &quot;550 5.1.1 User unknown&quot; We recent migration to Cloud Office 365.

External gmail sent to one user with know good address "550 5.1.1 User unknown" We recent migration to Cloud Office 365.