sendmail, 4th Edition

${cert_md5}

---

MD5 of cert certificate

V8.11 and above

As a part of the STARTTLS form of authentication and encryption, certificates are usually exchanged. This ${cert_md5} macro is assigned the result of an md5 (1) 128-bit " fingerprint " of the certificate presented by the other side. That value might look like this:

 5e5bb09c1a3488a3216aaabe23081caf 

The ${cert_md5} macro is not used in the default configuration file, but is available for use in rule sets of your own design. Note that a $& prefix is necessary when you reference this macro in rules (that is, use $&{cert_md5} , not ${cert_md5} ).

${cert_md5} is transient. If defined in the configuration file or in the command line, that definition can be ignored by sendmail .