Another frequent reason to send mail in Rmail is to forward the current message to other users. f (rmail-forward) makes this easy by preinitializing the *mail* buffer with the current message as the text, and a subject designating a forwarded message. All you have to do is fill in the recipients and send. When you forward a message, recipients get a message which is "from" you, and which has the original message in its contents.
Forwarding a message encloses it between two delimiter lines. It also modifies every line that starts with a dash, by inserting - at the start of the line. When you receive a forwarded message, if it contains something besides ordinary text--for example, program source code--you might find it useful to undo that transformation. You can do this by selecting the forwarded message and typing M-x unforward-rmail-message. This command extracts the original forwarded message, deleting the inserted - strings, and inserts it into the Rmail file as a separate message immediately following the current one.
Resending is an alternative similar to forwarding; the difference is that resending sends a message that is "from" the original sender, just as it reached you--with a few added header fields Resent-From and Resent-To to indicate that it came via you. To resend a message in Rmail, use C-u f. (f runs rmail-forward, which is programmed to invoke rmail-resend if you provide a numeric argument.)
The m (rmail-mail) command is used to start editing an outgoing message that is not a reply. It leaves the header fields empty. Its only difference from C-x 4 m is that it makes the Rmail buffer accessible for C-c C-y, just as r does. Thus, m can be used to reply to or forward a message; it can do anything r or f can do.
The c (rmail-continue) command resumes editing the *mail* buffer, to finish editing an outgoing message you were already composing, or to alter a message you have sent.
If you set the variable rmail-mail-new-frame to a non-nil value, then all the Rmail commands to start sending a message create a new frame to edit it in. This frame is deleted when you send the message, or when you use the Cancel item in the Mail menu.
All the Rmail commands to send a message use the mail-composition method that you have chosen (see Mail Methods).
