System and method for dual email and web based checkout in an unsegmented list

An e-commerce computer system that utilizes Simple Mail Transfer Protocol (SMTP) to improve security of the e-commerce computer system, the system comprising:

• a communications interface that is communicatively coupled to a client device and a vendor system via a network;
• a processor communicatively that is communicatively coupled to the communication interface, wherein the processor:
• receives, using the communication interface, an SMTP email message from the client device, wherein the SMTP email message includes an encrypted token that includes transaction information for a transaction from the vendor system and at least one key,
• authenticates the SMTP email message based on a sender of the SMTP email message;
• and
• on a condition that the SMTP email message is authenticated:
• decodes, using the at least one key, the encrypted token to form a decoded token,
• determines a customer email address and a registration status of a customer based on the decoded token, and
• sends, using the communication interface, an email message that utilizes SMTP to the customer email address based on the registration status determined.

A method that utilizes a mailto link to improve security of an e-commerce computer system, the method comprising:

• receiving, by a processor of the e-commerce computer system, an HTTP request from a vendor web page, wherein the HTTP request includes a request to perform a transaction;
• generating, by the processor, the mailto link and an encrypted token associated with the HTTP request, wherein the encrypted token includes at least one key;
• transmitting, by the processor, the mailto link and the encrypted token to the vendor web page, wherein the mailto link when selected generates an email response message addressed to the e-commerce computer system;
• receiving, by the processor, an SMTP email response that includes the encrypted token;
• authenticating, by the processor, the SMTP email response based on a sender of the SMTP email response;
• and
• on a condition that the SMTP email response is authenticated:
• decoding, by the processor, the encrypted token to form a decoded token using the at least one key,
• determining, by the processor, a customer and a registration status of a customer based the decoded token;
• and
• processing, by the processor, the transaction when the registration status determined indicates that the customer is a registered customer.