A typical mail program will allow one or more signature files.
A signature file is a file which contains any information one would like to append at the end of a mail message. It could like like:
---------------------------------------------------------------------------- Claude Cantin Claude Cantin Rm 3118, 100 Sussex Dr. Piece 3118, 100 Prom. Sussex Scientific Computing Support Soutien aux chercheurs Science Affairs Office Bureau des affaires scientifiques National Research Council Conseil National de Recherches Ottawa, Canada (K1A 0R6) Ottawa, Canada (K1A 0R6) claude.cantin@nrc.ca 1-613-993-0822 (FAX: 993-3127) ----------------------------------------------------------------------------
A typical signature filename is .signature.
Often, two such files are used: one for local mail (mail to addresses on the local system) and one for mail to remote users. The file names could be .lsignature and .rsignature.