where can I get the source for BSD mail?

I am looking for a copy of the source for BSD mail. Can anyone help me? ------------------------------------------------------------------------- To find out more about the anon service, send mail to help@anon.penet.fi. Due to the double-blind, any mail replies to this message will be anonymized, and an anonymous id will be allocated automatically. You have been warned. Please report any problems, inappropriate use etc. to admin@anon.penet.fi.