''${mail_host}'' '''


Saved $@ value for MAIL FROM: triple V8.10 and above

Upon receipt of the MAIL FROM: address, a delivery agent is selected by the RHS of a parse rule set 0 rule, which defines a triple that contains three pieces of information for that address:

$#delivery_agent $@ host  $:address  

The $@ portion of the triple contains the host to which to connect for delivery. For example:


Once that host is determined for the $@ part of the triple, it is copied to this ${mail_host} macro.

${mail_host} is transient. If it is defined in the configuration file or in the command line, that definition can be ignored by sendmail. Note that a $& prefix is necessary when you reference this macro in rules (that is, use $&{mail_host}, not ${mail_host}).

    Part I: Build and Install
    Part II: Administration
    Part III: The Configuration File
    Chapter 21. The D (Define a Macro) Configuration Command
    Chapter 24. The O (Options) Configuration Command