Yes, you can use SSL with your email at One.com.
SSL stands for Secure Sockets Layer, and is a protocol that protects communication over the internet. We recommend that you use SSL when you set up your email account in an email application to protect your data.
What about TLS?
TLS (Transport Layer Security) is a newer version of the SSL protocol, and can also be used to protect your email at One.com.
Check out our email setup guides or contact our support for further details about the settings for SSL/TLS in the mail application you use.