After you have opened an EaSecure message, you may select "Show EaSecure Message Hash" under the "Tools" menu to view the message hash of the message you have just opened. Message hash is a much stronger form of message ID. Each email message has a unique message ID to identify the particular message. However, message IDs offer no integrity protection to the messages. The message and the message ID can be easily tampered with.

Message hash, however, offers very strong integrity protection. It is not possible to tamper with the message without changing the message hash. If two EaSecure messages have the same message hash, their contents are guaranteed to be exactly the same. If you send an EaSecure message to multiple recipients, all the copies of the message, including the copy you have kept for your self will have exactly the same message hash.

For those interested in technical details, the EaSecure message hash is computed using SHA256, a new FIPS standard, much stronger than SHA1 and MD5 used in many other secure email systems.