Hi, 

I'm trying to delete one of two Zoho Mail users but getting above error message. 

The only other Zoho Service I'm using is Zoho One and Zeptomail but in none of these the user I'm trying to delete is registered. 

I'm in discussion with Zoho Support for several weeks now about this topic but they seem to be unable/unwilling to fix it. 

Has anyone an idea how I can solve this issue?