Chapter 22. The C and F (Class Macro) Configuration Commands

The configuration C and F class commands allow you to compare individual tokens to multiple strings when determining a match in the LHS of rules.

What’s New with V8.13

Under V8.13 sendmail, one of these classes has been modified, and two have been renamed:

  • The class $=w no longer is automatically filled with all domain prefixes.

  • Two existing class macros, $={tls} and $={src}, have been renamed (the first letter is now capitalized) to become $={Tls} and $={Src}.

The $=w Class Is Less Auto-Filled

Prior to V8.13, sendmail would automatically fill the class $=w (22.6.16[3ed]) with every possible form of domain address that it could find. Specifically, it would:

  1. Find your machine’s canonical hostname and add it to $=w—for example,

  2. Add each leading component of the canonical hostname to $=w—for example, mail and mail.bob.

  3. Look up additional hostnames associated with each network interface and add each to $=w—for example,

  4. Look up the IP addresses associated with each found name and add each found address (inside square braces) to $=w—for example, [].

  5. Reverse lookup each address and add the hostnames found for each (if not duplicated) to the class $=w—for example,

Beginning with V8.13, sendmail eliminates the second and fifth step and no longer automatically stores that information for you. If you needed sendmail to store that information in class $=w for you, ...

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