Sep 6, 2017

How to verify if the mail was sent over an encrypted channel by PowerMTA

To verify if the mail was sent over an encrypted channel, it is necessary to add additional fields to the CSV accounting file. This can be done with the following configuration:
<acct-file logacct.csv>
    records d, b
    record-fields d *, dlvTlsProtocol, dlvTlsCipher
    record-fields b *, dlvTlsProtocol, dlvTlsCipher
</acct-file>
If encryption is used, the above configuration will record the protocol and cipher used to deliver the message over an encrypted channel.