ExchangePro: Upon migrating from on-prem to O365, updating existing calendar event lead to NDR bo (4315463)

Issue

Upon migrating from on-prem to O365, updating existing calendar event lead to NDR bounce message. 

Error

This message could not be sent. Try sending the message again later, or contact your network administrator.  Error: [0x8007005-00000000-00000000].

Background

This behavior is by design and it seems to be related to ACL permissions not syncing to the cloud. This is a limitation of Microsoft and not our product but we do plan to address this in our future release. SendAs / Send-as permissions are not retained in migrations to Office 365 just because it is based on an ACL set in Active Directory and ACLs are not synced to Office 365.

Solution

To add a SendAs permission use the Add-RecipientPermission cmdlet with Exchange Online Remote PowerShell or use the Exchange Admin Control Panel and add the Send As permission from the “Mailbox Delegation” menu. Here is a KB that further explains the Add-RecipientPermission cmdlet :  

 https://technet.microsoft.com/en-us/library/ff935839(v=exchg.150).aspx

If that does not apply to your situation or resolve your issue then upgrade might be a recommended route based on Microsoft KB: 

https://support.microsoft.com/en-us/kb/2902929/en-us