Method for securely communicating email content between a sender and a recipient

A method for end-to-end encryption of electronic mail comprising:

• receiving an email encrypted according to a first encryption protocol, the email sent by a sender at a first domain and designating a recipient address within a second domain;
• in response to a sender exclusion list identifying the sender, passing the email encrypted according to the first encryption protocol to the recipient address;
• in response to the sender exclusion list excluding the sender, accessing encryption protocols supported by a recipient mail client at the recipient address;
• in response to the recipient mail client supporting the first encryption protocol, transmitting the email encrypted according to the first encryption protocol to the recipient address;
• and
• in response to the encryption protocols supported by the recipient mail client excluding the first encryption protocol:
• generating a notification email comprising a hyperlink to a secure webpage containing content of the email and an encryption opt-out option;
• transmitting the notification email to the recipient address;
• in response to selection of the encryption opt-out option, serving an electronic contract for disabling encryption of inbound emails from the first domain to the recipient address and for assuming liability by the recipient for data loss for inbound emails from the first domain to the recipient address;
• and
• in response to execution of the electronic contract, appending the recipient exclusion list with the recipient address.

A method for end-to-end encryption of electronic mail comprising:

• receiving an email, the email sent by a sender at a first domain and designating a recipient address;
• in response to the sender exclusion list excluding the sender:
• accessing encryption protocols supported by a recipient mail client at the recipient address;
• and
• in response to encryption protocols supported by the recipient mail client excluding a target encryption protocol:
• generating a notification email comprising a hyperlink to a secure webpage containing content of the email, and an encryption opt-out option;
• transmitting the notification email to the recipient address;
• in response to selection of the encryption opt-out option, serving an electronic contract for disabling encryption of inbound emails from the first domain to the recipient address and for assuming liability by the recipient for data loss for inbound emails from the first domain to the recipient address;
• and
• in response to execution of the electronic contract, appending the recipient exclusion list with the recipient address.

A method for end-to-end encryption of electronic mail comprising:

• receiving an email encrypted according to a first encryption protocol, the email sent by a sender at a first domain and designating a recipient address within a second domain;
• querying a recipient mail client at the recipient address for an enabled email port and a security level of the enabled email port;
• identifying a set of encryption protocols supported by the recipient mail client based on the enabled email port and the security level of the enabled email port;
• in response to a recipient exclusion list identifying the recipient address:
• encrypting the email to a second encryption protocol less robust than the first encryption protocol and supported by the recipient mail client;
• and
• transmitting the email encrypted according to the second encryption protocol to the recipient address;
• in response to the recipient exclusion list excluding the recipient address and the recipient mail client supporting the first encryption protocol, transmitting the email encrypted according to the first encryption protocol to the recipient address;
• in response to the recipient exclusion list excluding the recipient address and in response to a maximum encryption level supported by the recipient mail client exceeding the first encryption protocol:
• encrypting the email to a third encryption protocol exceeding robustness of the first encryption protocol;
• and
• transmitting the email encrypted according to the third encryption protocol to the recipient address;
• and
• in response to the recipient exclusion list excluding the recipient address and in response to encryption protocols supported by the recipient mail client excluding the first encryption protocol:
• generating a notification email comprising a hyperlink to a secure webpage containing content of the email;
• transmitting the notification email to the recipient address;
• in response to selection of the hyperlink at the recipient mail client executing on a computing device, serving the secure webpage containing content of the email and an encryption opt-out option to a web browser executing on the computing device;
• in response to selection of the encryption opt-out option, serving an electronic contract for disabling encryption of inbound emails from the first domain to the recipient address and for assuming liability by the recipient for data loss for inbound emails from the first domain to the recipient address;
• and
• in response to execution of the electronic contract, appending the recipient exclusion list with the recipient address.