A signature file is a file which contains any information one would like to append at the end of a mail message. It could look like:
---------------------------------------------------------------------------- Claude Cantin Claude Cantin Rm 2025, 100 Sussex Dr. Piece 2025, 100 Prom. Sussex Research Computing Support Soutien informatique en recherche Information Management Services Services de gestion de l'information 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 where local signature files are used for addresses without the at ("@") sign.
Signature files are automatically appended at the end of every message sent.