Qmail in public domain

If qmail is now in the public domain, that's good news: it means we can sue Bernstein for
qmail flooding our mailboxes with bounce messages, or for otherwise annoying us.

Seriously, the reason for not putting software into the public domain is that (as I understand
it) only a license gives you the power to make users of the software assume liability for
problems caused by running the code.  If you don't make the license to copy contingent on them
accepting liability, then people harmed by the software can come after *you*.  Of course they
might anyway, and if the person who copied the code has no money, a judge might allow it --
except of course *you* have no money either, right?  If you *do* have money, you're supposed
to hire a fixer to arrange that they sue somebody else instead.

(I am not a lawyer.  The above might just be superstition.)