Why so much Hotmail spam lately (was Re: [Mimedefang] Adding support for learning our addresses)

[David F. Skoll]

WBrown at e1b.org wrote:

> But wouldn't it be in Microsoft's best interest to prevent their servers 
> from being used to spam?

Maybe, but how would they do it?  Hotmail must have over 60 million
subscribers.  Their outgoing mail volume has to be on the order of
a billion a day.  Filtering that volume of e-mail, or even examining it
for trends, poses some pretty extreme technical difficulties.

> Even from the economic standpoint of reducing the load/number of
> servers required.

It's a heck of a lot cheaper to relay a billion messages than to filter
them.

> It would seem that they would see high levels of traffic coming from bots 
> that they could throttle/reject.

I wouldn't be surprised if more sophisticated bots use zombie networks to
log on to Hotmail and send mail via their Web interface.  I think it would
be pretty hard to notice an anomaly against all their regular traffic.

Regards,

David.