diff --git a/interface/web/mail/form/mail_user.tform.php b/interface/web/mail/form/mail_user.tform.php
index 3d1a8fde7fa5b0afe5a56ffdb2a38c456d3849e6..8fb6c4a69227b51a66c7d41cd1b57c0aab9b5a51 100644
--- a/interface/web/mail/form/mail_user.tform.php
+++ b/interface/web/mail/form/mail_user.tform.php
@@ -187,7 +187,7 @@ $form["tabs"]['mailuser'] = array(
 			'default' => '',
 			'value'  => '',
 			'width'  => '30',
-			'maxlength' => '255'
+			'maxlength' => '65535'
 		),
 		'sender_cc' => array (
 			'datatype' => 'VARCHAR',