This error is often caused by a proxy or firewall blocking the connection between the Egress client and switch.egress.com. When the client cannot connect it can sometimes place itself in "Offline Mode" which will impact the ability to send secure emails
The issue can be resolved by whitelisting the following URLs:
Large File Transfer:
By default, Large File Transfers are uploaded to Amazon S3 (Ireland). Please refer to Amazon's Support page for the correct URLs to whitelist according to the location of your Amazon instance:
If you are unsure where your Amazon S3 instance is located, raise a ticket with Support who will be able to advise.
Additionally, ports 80 and 443 should be open to allow access for switch.egress.com.