This is my preferred method for sending ASCII messages that are longer than a couple of lines.
The GNU emacs editor has a built-in mail feature that is activated by typing Ctrl-x m from any window. This command opens a buffer called *mail*. At the top of this buffer you may fill in the address and subject. Below the line -text follows this line- you prepare your message using the full editing features of the text editor. For example, you may insert a file into this buffer using the emacs command Ctrl-x i <filename>. To create a Cc: line, type Ctrl-cfc. When you are ready to send the message, type Ctrl-c Ctrl-s. Use Ctrl-x b <Enter> to return to your previous emacs buffer when you are done.