Secure email verification service

A computer storage medium having computer-executable instructions stored thereon that, when executed by a processor, cause the processor to perform operations comprising:

• receiving, from a sender device that is used to send an email message, verification data comprising a sender identifier, a global time indicator, and message-specific data associated with the email message;
• identifying a user identifier associated with the sender identifier;
• generating a hash value of the user identifier, the global time indicator, and the message-specific data;
• sending the hash value to the sender device, wherein the sender device includes the hash value in the email message when the email message is sent;
• receiving, from a recipient device that receives the email message, a verification package that comprises the hash value and a recipient device version of the verification data;
• identifying a further user identifier associated with the sender identifier indicated by the recipient device version of the verification data;
• generating a new hash value of the further user identifier, a recipient global time indicator included in the email message received by the recipient device, and recipient message-specific data included in the email message received by the recipient device;
• and
• comparing the new hash value to the hash value to determine if the email message should be verified, wherein the user identifier is not known by the sender device or by the recipient device.

A method comprising:

• receiving, by a processor that executes a secure email verification service and from a sender device that is used to send an email message, verification data comprising a sender identifier, a global time indicator, and message-specific data associated with the email message;
• identifying, by the processor, a user identifier associated with the sender identifier;
• generating, by the processor, a hash value of the user identifier, the global time indicator, and the message-specific data;
• sending, by the processor, the hash value to the sender device, wherein the sender device includes the hash value in the email message when the email message is sent;
• receiving, by the processor and from a recipient device that receives the email message, a verification package that comprises the hash value and a recipient device version of the verification data;
• identifying, by the processor, a further user identifier associated with the sender identifier indicated by the recipient device version of the verification data;
• generating, by the processor, a new hash value of the further user identifier, a recipient global time indicator included in the email message received by the recipient device, and recipient message-specific data included in the email message received by the recipient device;
• and
• comparing, by the processor, the new hash value to the hash value to determine if the email message should be verified, wherein the user identifier is not known by the sender device or by the recipient device.