As accounts are free and you can easily create tens of them, per account
limits don't solve the problem.
Most free mail service providers allow their users to send through SMTP and
we would prefer to do that as well.
Content based filtering may be the way to go indeed - thank you for pointing
it.
Many thanks
--
Marcin Szymonik
szymoni...@gmail.com
I imagine most freemail providers keep a close eye on their abuse
mailboxes, limit the amount of mail that can be sent from any account in a
period of time (and the number of recipients in a single message), and
more than likely run some sort of bayesian (any sort of learning algo
would do) outgoing filter, as well as their incoming ones.
I'd personally stop allowing people to relay through you (unless they have
proven themselves through some arbitrary period of not sending spam), and
by default allow only sending from inside your webmail application. That's
only a place to start, imho.
Nick
