In order to secure the Egress platform, we use SSL certificates to enable HTTPS which allows a secure connection from your browser to our service.

Occasionally we may need to update our certificates in order to maintain this level of security. If you have a corporate environment, certain network traffic could be blocked which could break this secure connection, and you may experience an error when signing into our service online or via the Egress Client for Windows.

Your connection is not private. Attackers might be trying to steal your information from (for example, passwords, messages, or credit cards). NET::ERR_CERTIFICATE_TRANSPARENCY_REQUIRED

Egress Client for Windows


Alternative error: The underlying connection was closed: Could not establish trust relationship for the SSL/TLS secure channel.

This could be for the following reasons:

  1. Use of a cached copy of the certificate
  2. Trusted Root (and other certificates in the chain) have not been installed

NB: If you are using an on-premise Egress Gateway, mail will be queued if the new certificate cannot be trusted. Ensure that the Gateway can access the above locations.

As IT Administrator, make sure that:

If your organisation is still experiencing errors connecting to our platform, please contact Egress Support.

Have more questions? Submit a request