Add config bit to tell fmn frontend where bastion is.

roles/notifs/frontend/templates/fmn.web.py

@@ -25,6 +25,9 @@ config = {
     },
     {% endif %}
 
+    # We need to know this to call VERFY to validate new addresses.
+    "fmn.email.mailserver": "bastion01.phx2.fedoraproject.org:25",
+
     # Some configuration for the rule processors
     "fmn.rules.utils.use_pkgdb2": True,
     {% if env == 'staging' %}