Effective June 5th 2014, all emails sent via YAPI will utilize opportunistic encryption using TLS. 

For a long time, we have supported encryption for submitting messages to our email provider SendGrid. Now when your message is delivered to its recipient SendGrid will negotiate an encrypted TLS connection with the recipient’s mail server.

This means that as long as the message recipients’ mail server is configured to properly support TLS, it will be impossible for a passive adversary along the route to intercept and/or modify the message.

Learn more about Opportunistic Encryption.