Make email checks case insensitive. #5440

includes/checkout/functions.php

@@ -269,6 +269,7 @@ function edd_is_email_banned( $email = '' ) {
 		return false;
 	}
 
+	$email         = strtolower( $email );
 	$banned_emails = edd_get_banned_emails();
 
 	if( ! is_array( $banned_emails ) || empty( $banned_emails ) ) {
@@ -277,12 +278,24 @@ function edd_is_email_banned( $email = '' ) {
 
 	$return = false;
 	foreach( $banned_emails as $banned_email ) {
+
+		$banned_email = strtolower( $banned_email );
+
 		if( is_email( $banned_email ) ) {
+
+			// Complete email address
 			$return = ( $banned_email == $email ? true : false );
-		} elseif ( strpos( $banned_email, '.' ) === 0 ) { // Domains only
+
+		} elseif ( strpos( $banned_email, '.' ) === 0 ) {
+
+			// TLD block
 			$return = ( substr( $email, ( strlen( $banned_email ) * -1 ) ) == $banned_email ) ? true : false;
+
 		} else {
+
+			// Domain block
 			$return = ( stristr( $email, $banned_email ) ? true : false );
+
 		}
 
 		if( true === $return ) {