''${if_family_out}'' '''


The network family of the send interface V8.12 and above

The sendmail program can send SMTP email over one or more network interfaces, where each interface can have one or more addresses associated with it. When sendmail sends a network email message, it begins by connecting to a host on the network. Once that connection has been made (once the other site accepts the connection), sendmail records in the ${if_addr_out} macro the address associated with the interface over which it made that outbound connection. It then records the family to which that address belongs in the ${if_family_out} macro. The family is a text representation of an integer value that represents the family, as defined in sys/socket.h. A value of 2, for example, could represent the AF_INET family.

${if_family_out} is available for use in rule sets, and can be useful for rejecting spam or restricting connections to particular addresses. Note that a $& prefix is necessary when you reference this macro in rules (that is, use $&{if_family_out}, not ${if_family_out}).

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

    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