Cannot create Contact in Exchange Online
Published: Thursday, 21 June 2018 | Categories: Office 365 | Keywords: Contact | Status: Posted | Created: Thursday, 21 June 2018 | Author: paul

When trying to create a new contact in Exchange Online it fails with the error below:

Cannot create Contact
The proxy address "SMTP:[email protected]" is already being used by the proxy addresses or LegacyExchangeDN of "joe.bloggs_domain.com#EXT#". Please choose another proxy address.( The "MailUser" with display name "Joe Bloggs" is already setup and using the same address.)
This is due to the email address already being used for a guest users account. Guest user account addresses are not displayed within Exchange Online. The only way to create the contact is currently to delete the guest account (which removes all their Sharepoint permissions) and then create the contact.
1. Delete the “guest user” MailUser object in Exchange Online 
Get-MailUser [email protected] | Remove-MailUser 
2. Create the MailContact 
3. Add the MailContact 
Then the user will have to be added to Sharepoint again and access configured to the sites they previously had access to.


Add Comment
No Comments.