The draft says:
,----
| 3. Action addheader
|
| Syntax:
| "addheader" <name: string> <value: string>
|
| The addheader action appends a header field to the existing
| message header.
`----
Prepending would be a better default.
It is problematic that the user cannot control where the header is
inserted. I mentioned Received: earlier, but apparently that example
wasn't credible, so here is another, different, example. There are
more headers that are order dependent, in case this isn't a credible
example either.
Consider the following usage:
set mydatestring ...;
set mymsgidstring ...;
if header :contains "Subject" "libidn" {
addheader "Resent-From" "Simon Josefsson <simon(_at_)josefsson(_dot_)org>";
addheader "Resent-Date" $mydatestring;
addheader "Resent-Message-ID" $mymsgidstring;
redirect "bug-libidn(_at_)gnu(_dot_)org";
}
I'm not sure I think this is legitimate usage, but in any case, I'd argue for
prepend since that's how headers are normally added.
Ned