I use core_user_create_users function to create a user, and it works perfectly,
but when email adresse exist, then i have got a message "incorrect parameter" and in debug : "this email exist"
So i want to check by webservice if a email existe and or something like : "getuseridbyemail function" that can return me an id of a specific email.
I don't want to check it directly by SQL,
Thanks for your help