Microsoft 365 (Outlook on the web) - Error - The sharing invitation couldn't be sent/deleted
- Adding/Sharing a new user
- Removing/Deleting an existing user
Important: Even though you received this error, the action (adding or removing permissions) you performed was completed successfully. It's only that the user you added/deleted did not receive an email notifying them of this change.
Reason for error
This action requires that you have the ability to either 'send as' or 'send on behalf of' the account. At this time, you only have full mailbox permissions to this account.
Fix this error
If you want users to receive the email notification automatically, grant the account that is managing these permissions 'delegate' rights to the calendar of the account. Note: If you are granting these permissions to a service account, it must be viewable in the Global Address List). Delegate rights provide the user with 'editor' and 'send on behalf of' rights.