mimesend [-n] [-t to] [-s subj] (-f file [-m type])+ -n Don't actually send it; just print it to stdout. -t to The "to" address. -s subj The subject of the message. -f file Path to attached file, or - for STDIN. -m type MIME type of previous -f; therefore -m must follow -f.
For example:
mimesend -t you@yourhost.com -s "Hello, nurse!" -f greetings.htm -f foo.gif
8 Jan 1997