Use Encyro from Gmail
Install the Encyro addon for Gmail and read incoming secure messages or uploads directly from within Gmail. You may also download files and securely reply, reply-all, or forward a secure message.
The addon also lets you send secure messages and electronic signature requests directly from within Gmail. In short, all the commonly used Encyro functionality can be accessed within Gmail, and you would only need to login to the Encyro website for infrequent tasks such as changing your settings.
Some of the functionality is also available from the Gmail mobile app on your iOS or Android device. Once you install the addon in your Gmail account, it will be available on all your devices automatically.
Here are the instructions to install the Encyro addon for Gmail.