add permissions in ticket models

core/tickets/models.py

@@ -55,6 +55,12 @@ def create_issue_thread(sender, instance, created, **kwargs):
     if created:
         StateChange.objects.create(issue_thread=instance, state='pending_new')
 
+    class Meta:
+        permissions = [
+            ('send_mail', 'Can send mail'),
+            ('add_issuethread_manual', 'Can add issue thread manually'),
+        ]
+
 
 class Comment(models.Model):
     id = models.AutoField(primary_key=True)