How can you get sendmail to report what IP a mail came from?

[Burke, Thomas G.]

Hey all,

	I just noticed this in my logs:

Jul 28 12:55:19 tomii-gate sendmail[1016]: j6SGtI901016:
<a1aaa1azzzz1zaaaaa at tomii.dnsalias.com>... User unknown

	Anyone know off-hand where I should look to figure out where
that came from?  (My machine is tomii-gate)

	-Tom