Firewall settings can prevent the Threema Work app from establishing a connection to the Threema server, or they might block access to the management cockpit. To resolve this issue, please open the appropriate TCP ports.
Threema Work app: TCP ports 443 and 5222 need to be open for outgoing connections. Messages are transmitted through port 5222; port 443 serves as fallback in case of delays. For directory queries (synchronization of contacts, etc.) and media transmissions, HTTPS port 443 is used.
Threema calls: UDP port 3478 needs to be open for outgoing connections.
Threema group calls: UDP ports 22500–22532 need to be open for outgoing connections.
Management cockpit: TCP port 443 needs to be open for outgoing HTTPS connections.
If you experience connectivity issues with the desktop app or the web client, please refer to this FAQ article.
