it looks like there is some sort of deadlock situation on updating some mail and user accounts.
The only way out is deleteing the account and recreating it, but then I run into the error message :-
"The user with the name root-aarongray-org does already exist."
"Duplicate Email Address."
"A user with administrator rights does already exist for this site."
Sorry about this but this whole "user & Email" area seems really buggy.
Deleteing everything and emptying the recycle bin worked. But then it seems if you make a mistake along the way you have to delete everthing and start again.