AOL have a facility with their e-mail that only accepts mail from
addresses in the indivual's address book Is this unique to AOL or
can it be used with other servers ie Yahoo?
Richard
As far as I know, neither GMail nor Yahoo Mail provide a
straightforward way to only accept messages which are purportedly
from senders in your address book. However, this is not a widely
accepted method of blocking spam because (1) the From: header is
easy to forge, and (2) what if someone new wants to send you an
email?
What GMail and Yahoo *do* support are two effective and flexible
means of recognizing non-spam messages, Sender Policy Framework and
DomainKeys/DKIM. You can read about them here:
http://antispam.yahoo.com/domainkeys
http://www.openspf.org/Introduction
Since you're asking about Yahoo in comparison with AOL, I take it
that you're considering switching email service providers. In that
case, I highly recommend GMail -- it's very good all around, and its
spam filter is top notch (which would make sense, come to think of
it; filtering spam does fit within the company's core competency of
organizing information).