mouss writes:

> ahuh? how would spf fix the problem if spam gets out from an
> authorized client (yahoo, google, hotmail, aol, ...). however you
> respond, you'll find out that such (ougoing) spam problem isn't fixed
> _by_ SPF. In particular, don't tell me "they will fix their outgoing
> spam".

If you publish a suitable SPF record then you will not receive any
backscatter (which is the subject of this thread) from sites which
correctly implement SPF checking. Do not forget that SPF is not an
anti-spam too per-se but an anti-forgery one. Backscatter is one of the
problems which SPF fixes.