diff --git a/helpdesk/models.py b/helpdesk/models.py
index f2d13dbe..df4b1711 100644
--- a/helpdesk/models.py
+++ b/helpdesk/models.py
@@ -372,6 +372,7 @@ class Ticket(models.Model):
 
     submitter_email_id = models.CharField(
         _('Submitter E-Mail ID'),
+        max_length=256,
         blank=True,
         null=True,
         help_text=_("The Message ID of the submitter's email."),