As part of the RFC2554 authentication scheme, a client can ask if a user other than the envelope sender is allowed to authenticate on behalf of the envelope sender. This is done by adding an AUTH= parameter to the MAIL FROM: keyword: MAIL FROM: <user@host.domain> AUTH= address This ${auth_author} macro is assigned the address that followed the MAIL FROM: AUTH= extension. The ${auth_author} macro is useful for adding your own rules to the Local_trust_auth rule set. Note that a $& prefix is necessary when you reference this macro in rules (that is, use $&{auth_author} , not ${auth_author} ). ${auth_author} is transient. If defined in the configuration file or in the command line, that definition can be ignored by sendmail . |