GCM/FCM broken with Bitmask on
We got several complaints, that when people have Bitmask on, they don't receive application updates nor messages that all go over the Google messaging platform. No application updates is a security bug, even if they come from the Play Store. Not receiving Signal Messages might be perceived by some as a security enhancement or used as an argument to convince Moxie to start federation, however in the current state, it simply annoys users and they'll stop using Bitmask.
I suspect it be caused by https://leap.se/code/issues/8140
https://developers.google.com/cloud-messaging/http mentions this:
Note: If your organization has a firewall that restricts the traffic to or from the Internet, you'll need to configure it to allow connectivity with GCM. The ports to open are: 5228, 5229, and 5230. GCM typically only uses 5228, but it sometimes uses 5229 and 5230. GCM doesn't provide specific IPs. It changes IPs frequently. We recommend against using ACLs but if you must use them, take a broad approach such as the method suggested in this support link.
I currently don't have access to a Bitmask on Android client configured to a provider where I can change firewall rules at will to test this out.
(from redmine: created on 2016-09-09)