When modifying admin's personal info in Parallels Plesk Panel GUI following error occurs:
Error: Unable to update administrator information: This e-mail address is already in use. Please specify another address.
Note: This issue has been completely fixed in Plesk 11.5
There was possibility to create client with the same email as admin in earlier Parallels Plesk Panel versions. Typically it was
mydomains client. In 10.x versions it is prohibited to use the same email for different users (admin and client).
For Plesk versions older than 10.x locate a client with the same email as admin (typically it's
mysql> select login, pname from clients, misc where misc.param="admin_email" and clients.email=misc.val;
and change the client's email address.
For Plesk 10.x versions locate a user with the same email as:
# mysql -uadmin -p`cat /etc/psa/.psa.shadow` psa -e "select id, login, email, contactName from smb_users where firstname.lastname@example.org';"
Find the corresponding user in the Parallels Plesk Panel and change the user's email to another one.