Yank the message that's being replied to into the message buffer (message-yank-original).

Fill the yanked message (message-fill-yanked-message). Warning: Can severely mess up the yanked text if its quoting conventions are strange. You'll quickly get a feel for when it's safe, though. Anyway, just remember that C-x u (undo) is available and you'll be all right.

Insert a signature at the end of the buffer (message-insert-signature).

All headers that match this regexp will be removed from yanked messages. The default is `.', which means that all headers will be removed.

Function called to insert the citation line. The default is message-insert-citation-line, which will lead to citation lines that look like:

Hallvard B Furuseth <h.b.furuseth@usit.uio.no> writes:

Point will be at the beginning of the body of the message when this function is called.

When you are replying to or following up an article, you normally want to quote the person you are answering. Inserting quoted text is done by yanking, and each quoted line you yank will have message-yank-prefix prepended to it. The default is `> '. If it is nil, just indent the message.

Number of spaces to indent yanked messages.

Function for citing an original message. The default is message-cite-original, which simply inserts the original message and prepends `> ' to each line. message-cite-original-without-signature does the same, but elides the signature. You can also set it to sc-cite-original to use Supercite.

Function for modifying a citation just inserted in the mail buffer. This can also be a list of functions. Each function can find the citation between (point) and (mark t). And each function should leave point and mark around the citation text as modified.

String to be inserted at the end of the message buffer. If t (which is the default), the message-signature-file file will be inserted instead. If a function, the result from the function will be used instead. If a form, the result from the form will be used instead. If this variable is nil, no signature will be inserted at all.

File containing the signature to be inserted at the end of the buffer. The default is `~/.signature'.