How to append .signature in mail

Wed Feb 28 18:16:24 AEST 1990

I know Pnews automatically append my .signature file to the end of the
  article.  But how does one do it for mail or emacs sendmail?
  Thanks in advance.

-  Yue-shun

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  Yue-shun E. Ho					  yho at ee.cornell.edu
  201 Maple Ave, #E30, Ithaca, New York, USA 14850-4903      +1 607 273 7214
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