email_exists() WP 1.0

Checks whether the given email exists.

For more information on this and similar theme functions, check out the Conditional Tags article in the Theme Developer Handbook.

Works based on: get_user_by()

No Hooks.

Int/false. The user's ID on success, and false on failure.

email_exists( $email );

<?php
function email_exists( $email ) {
	$user = get_user_by( 'email', $email );
	if ( $user ) {
		return $user->ID;
	}
	return false;
}