Delegates continually re-appearing in Skype for Business / Lync

So I recently had an issue I was called out to address at a customer’s environment where the delegate sync notification “You were added as a delegate for Joe Blogs” would appear over and over for a multitude of users

The first this was to check was that it was being correctly logged in the users registry as a dismissed delegate in the following Key

 "HKEY_CURRENT_USER\SOFTWARE\Microsoft\Office\15.0\Lync\[email protected]\Dismissed DelegatorList" 

 

I also checked for Exchange Delegate sync by running the following cmdlets

Get-CsClientPolicy |where {$_.EnableExchangeDelegateSync -eq $true} | findstr "Identity"

This finds any policy that enables delegate sync and displays its name, as it was defined on the Global client policy I also run

Get-CsClientPolicy |where {$_.EnableExchangeDelegateSync -eq $false} | findstr "Identity"

To find any policy where the value has been set to False at a more granular level.So after some digging we noticed that the delegators (that is the users that have delegated access to another user) had since left the company.A quick check with Get-csuser showed the user no longer existed in Skype4B

But as per company policy, they still existed in AD and were disabled. (this may be unrelated)

However, when checking with Sefautil, we can see the users delegates are still stored in the Skype4B Database.

 SEFAUtil.exe /server:frontend.skype4badmin.com [email protected] 

 

Thus as we know the users delegate status is stored in the Skype4B SQL server, we can manipulate it directly using sefautil like this.

SEFAUtil.exe /server:frontend.skype4badmin.com [email protected] /Removedelegate:[email protected] 

Now the user will stop getting prompted to accept delegate rights for a user that doesn’t existHope this helps.