Myriad of payment methods with alternate payment controls

A non-transitory computer-readable storage medium storing instructions that, when executed by one or more processors, cause the one or more processors to perform operations comprising:

• assigning a transaction-specific email address for a transaction, the transaction-specific email address being associated with a token that encodes at least a transaction identifier and an expiration time;
• receiving, via SMTP, a message addressed to the transaction-specific email address;
• authenticating the message, the authenticating comprising:
• (i) evaluating a Domain-based Message Authentication, Reporting & Conformance (DMARC) policy for a domain indicated in a From header of the message and confirming identifier alignment between the From header domain and at least one of a DomainKeys Identified Mail (DKIM) signing domain or a Sender Policy Framework (SPF) authenticated domain, and (ii) decoding the token and verifying the token using a public key corresponding to a private key of a system and determining that the expiration time has not elapsed;
• and
• performing an action for the transaction only when the authenticating in (i) and (ii) succeeds.

A system for providing an email as a command that improves security of a transaction using Simple Mail Transfer Protocol (SMTP), the system comprising:

• a communication interface;
• a memory;
• and
• one or more processors communicatively coupled to the communication interface and the memory, the one or more processors configured to:
• assign a transaction-specific email address for the transaction, the transaction-specific email address being associated with a token that encodes at least a transaction identifier and an expiration time;
• receive, via SMTP, a message addressed to the transaction-specific email address;
• authenticate the message by (1) evaluating a Domain-based Message Authentication, Reporting & Conformance (DMARC) policy for a domain indicated in a From header of the message and confirming identifier alignment between the From header domain and at least one of a DomainKeys Identified Mail (DKIM) signing domain or a Sender Policy Framework (SPF) authenticated domain, and (ii) decoding the token and verifying the token using a public key corresponding to a private key of the system and determining that the expiration time has not elapsed;
• and
• perform an action for the transaction only when the authenticating in (i) and (ii) succeeds.