"All-round encryption and zero knowledge
We encrypt everything possible: Your entire inbox, your contacts and all other data that you can store in Tutanota (e.g. a calendar will be added in an upcoming release). When you send an end-to-end encrypted email, everyhting - subject, content and all attachments - is automatically encrypted. We also encrypt the messages that you receive unsecurely from other email providers. You can find details on that"
"Gpg4win - a secure solution...
... for file and email encryption. Gpg4win (GNU Privacy Guard for Windows) is Free Software and can be installed with just a few mouse clicks."
"Enigmail is a security extension to Mozilla Thunderbird and Seamonkey. It enables you to write and receive email messages signed and/or encrypted with the OpenPGP standard."
SSL certificates, short for Secure Socket Layer, were developed by Netscape to secure online transactions between web servers and web browsers. SSL certificates can help protect an online user's banking details, login credentials, email addresses, and other confidential information with first-rate encryption strength, keeping it nice and secure and away from the ruthless eyes of hackers.