Name
${currHeader}
Synopsis
The ${currHeader}
macro is given a value whenever
a header-checking rule set is called. Header rule set checking is
declared as part of the H
configuration command,
as for example:
LOCAL_RULESETS HSubject: $>ScreenSubject
Here, sendmail will gather the text following
the Subject
: header in the mail message and supply
that text to the ScreenSubject
rule set. Usually,
that text is treated as an address. All RFC comments are stripped and
extra interior spaces are removed, but when you want that text to be
supplied intact and as is to a rule set, you can employ this
${currHeader}
macro.
To illustrate, consider the need to reject messages that have 10 or
more consecutive spaces in the Subject
: header.
Such Subject
: headers often indicate a spam
message:
Subject: Rates DROPPED! Lenders COMPETE for mortgage LOANS! 83419
One way to screen for such headers might look like this:
LOCAL_CONFIG Ksubjspaces regex -a.FOUND [ ][ ][ ][ ][ ][ ][ ][ ][ ][ ] LOCAL_RULESETS HSubject: $>+ScreenSubject SScreenSubject R $* $: $1 $(subjspaces $1 $) ← won't work R $* . FOUND $#error $@ 5.7.0 $: "553 Subject: header indicates a spam." R $* $: OK
The K line sets up a regular expression that will look for 10
consecutive space characters. The first rule in the rule set attempts
to find 10 consecutive spaces in the workspace by passing the
workspace to the subjspaces
regular expression
map.
But this won’t work. The workspace contains the
Subject
: header’s text after that text has been stripped ...
Get Sendmail, 3rd Edition now with the O’Reilly learning platform.
O’Reilly members experience books, live events, courses curated by job role, and more from O’Reilly and nearly 200 top publishers.