Recall that a header line declaration looks like the following:
H begins the line and tells
sendmail that a header definition follows. The
expression causes sendmail to include the header
only if one of the
flags is found in the
selected delivery agent’s
equate. As you saw in the previous section, beginning with V8.10, a
macro name can replace the
name and a colon then follow.
Beginning with V8.10, sendmail allows the name
of a rule set to replace the
That rule set declaration can come in two forms:
Hname: $> rule set Hname: $>+ rule set← don't strip comments
Both forms basically say the same thing: if
sendmail finds a header
name already in a message it is processing, it
passes the existing header
field to the
rule set indicated. The
+ in the second form tells
sendmail to leave intact (not strip)
parenthesized RFC2822 comments from the passed
$> in the earlier declaration passes just
text to the rule set, while
$>+ passes the unstripped text with RFC2822
If the rule set specified is not a legal rule set name, or if it is missing, the following error will be printed and logged:
cf file name: line number: invalid rule set name: "bad name"
If the named rule set does not exist in the configuration file, the effect is the same as if it did exist and had returned a legal value.
Rule sets called to process headers can return two possible rejection values, ...