qmail Memphis RPM relaying by default?

[Nicolas MONNET]

I had to reinstall Qmail a couple months ago, and used the Memphis RPM. I
didn't pay much attention to default parameters, as I copied qmail/control
from my old install. Well it turns out that Memphis is using tcprules, and
tcprules.d/qmail-smtpd happened to be:

:allow,RELAYCLIENT=""

... Which I found out the hard way after a spammer used my system as a
relay ... 

Doh!

I don't know how it got set up that way.