Email protection using email signatures based on signing tokens

A non-transitory processor-readable storage medium having stored therein program code of one or more software programs, wherein the program code when executed by at least one processing device causes the at least one processing device to perform the following steps:

• obtaining a signed email sent by at least one sending processing device of an email sender, wherein the signed email is based at least in part on a source email, wherein a first hash value generated using the source email is used as a key to at least one data record, wherein the signed email comprises a second hash value as an email signature, and wherein the second hash value is (i) generated using the source email embedded with at least a portion of a signing token of the email sender and (ii) stored in the at least one data record;
• obtaining the second hash value from the signed email;
• comparing the second hash value obtained from the signed email to one or more of:
• (i) a copy of the second hash value obtained from the at least one data record and (ii) a comparison value determined using a regenerated version of the source email embedded with the at least the portion of the signing token of the email sender;
• and
• automatically controlling a delivery of the signed email to at least one email recipient based at least in part on a result of the comparison.

An apparatus comprising:

• at least one processing device comprising a processor and a memory, wherein the processor is coupled to the memory;
• the at least one processing device being configured to implement the following steps:
• obtaining a signed email sent by at least one sending processing device of an email sender, wherein the signed email is based at least in part on a source email, wherein a first hash value generated using the source email is used as a key to at least one data record, wherein the signed email comprises a second hash value as an email signature, and wherein the second hash value is (i) generated using the source email embedded with at least a portion of a signing token of the email sender and (ii) stored in the at least one data record;
• obtaining the second hash value from the signed email;
• comparing the second hash value obtained from the signed email to one or more of:
• (i) a copy of the second hash value obtained from the at least one data record and (ii) a comparison value determined using a regenerated version of the source email embedded with the at least the portion of the signing token of the email sender;
• and
• automatically controlling a delivery of the signed email to at least one email recipient based at least in part on a result of the comparison.