When you’re out and about and there is an important email you are asked to respond to immediately. There could be troubles reaching the Webmail with café, hotel or corporate networks.
These networks usually have firewall that block access ports such as 2095 or 2096. These ports are used to access your Control Panel. These networks usually mitigate their networks security by closing all unused ports. However, you may check this guided link to more ways on how to access webmail.