Recommended Headers
Every sendmail.cf file should have a minimal complement of header definitions. Here we present a recommendation. Don’t use this as is. The details are not generic to all versions of sendmail, nor are they appropriate for all sites:
H?P?Return-Path: $g HReceived: $?sfrom $s $.by $j ($v/$V) id $i; $b ← mandatory H?D?Date: $a ← mandatory H?F?From: $q ← mandatory H?x?Full-Name: $x H?M?Message-Id: <$t.$i@$j> ← mandatory H?D?Resent-Date: $a ← mandatory H?F?Resent-From: $q ← mandatory H?M?Resent-Message-Id: <$t.$i@$j> ← mandatory
Each of these is described individually at the end of
this chapter. Except for Received: (Received: on page 1162), none is
added to any mail message that already has that
particular header present.
The Return-Path:
header (Return-Path: on page
1165) is removed if present, and is added only if
the delivery agent for the recipient has the
F=P flag
present. Similarly, the Date: relies on F=D, the From: relies on F=F, the Full-Name: relies on
F=x, and the
Message=Id:
relies on F=M.
Of those shown, only the seven indicated are truly mandatory and must be declared in every configuration file. The others are highly recommended.
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