The message-wide-reply pops up a message buffer that’s a wide
reply to the message in the current buffer. A wide reply is a
reply that goes out to all people listed in the To, From
(or Reply-To) and CC headers.
Message uses the normal methods to determine where wide replies are to go,
but you can change the behavior to suit your needs by fiddling with the
message-wide-reply-to-function. It is used in the same way as
message-reply-to-function (see Reply).
Addresses that match the message-dont-reply-to-names regular
expression (or list of regular expressions or a predicate function)
will be removed from the CC header. A value of nil means
to exclude only your email address.
message-prune-recipient-rules is used to prune the addresses
used when doing a wide reply. It’s meant to be used to remove
duplicate addresses and the like. It’s a list of lists, where the
first element is a regexp to match the address to trigger the rule,
and the second is a regexp that will be expanded based on the first,
to match addresses to be pruned.
It’s complicated to explain, but it’s easy to use.
For instance, if you get an email from ‘foo@example.org’, but
‘foo@zot.example.org’ is also in the CC list, then your
wide reply will go out to both these addresses, since they are unique.
To avoid this, do something like the following:
(setq message-prune-recipient-rules
'(("^\\([^@]+\\)@\\(.*\\)" "\\1@.*[.]\\2")))
If, for instance, you want all wide replies that involve messages from ‘cvs@example.org’ to go to that address, and nowhere else (i.e., remove all other recipients if ‘cvs@example.org’ is in the recipient list:
(setq message-prune-recipient-rules
'(("cvs@example.org" ".")))
If message-wide-reply-confirm-recipients is non-nil you
will be asked to confirm that you want to reply to multiple
recipients. The default is nil.