Firewall settings

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.

Management cockpit: TCP port 443 needs to be open for outgoing HTTPS connections.

If you experience connectivity issues with Threema Web, please refer to this FAQ article.