Header Names
The name
portion of the
H
configuration command must be one of the names
shown in Table 25-1. Other names do not produce an
error but might confuse other programs that need to process them.
Names marked with an asterisk are defined by RFC2822.
apparently-to |
bcc* |
cc* |
comments* |
content-length |
content-transfer-encoding |
content-type |
date* |
disposition |
encrypted |
errors-to |
from* |
full-name |
in-reply-to* |
keywords* |
mail-from |
message |
message-id* |
notification-to |
posted-date |
precedence |
received* |
references* |
reply-to* |
resent-bcc* |
resent-cc* |
resent-date* |
resent-from* |
resent-message-id* |
resent-reply-to |
resent-sender* |
resent-to* |
return-path* |
return-receipt-to |
sender* |
subject* |
text |
to* |
via |
x400-received |
These are discussed individually in Section 25.12 at the end of this chapter.
The RFC2822 standard allows a
special form to be used for creating custom header names. All mail
programs, including sendmail, are required to
accept and pass through as is any header name that begins with the
special characters x-
. The following header
definition, for example, can be used to introduce information that
your site is running an experimental version of
sendmail:
HX-Beware: This message used an experimental version of sendmail
The name
part of header definitions is
case-insensitive. That is, X-Beware
,
x-beware
, and X-BEWARE
are all
the same. For example, when sendmail checks for
the To:
header internally, it will recognize it regardless ...
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