Cannot add certain user in AdobeSign

[Guest]

I've just started using Adobe Sign, and I've added a couple of my employees, but I am unable to add one email address in particular.

I keep getting an error message that says "cannot add this email address." My employee doesn't have any other Adobe account, so I'm not sure why this is happening. I've been able to add everyone else without a problem.

[AadeshSingh]

Duplicate thread, please refer to the same.  Unable to add users