Hotmail blackholing certain IP ranges ?

Yeah, Hotmail's spam filtering recently got very aggressive. The short
version is that they are being pounded so hard by botnets and other
malicious spam/phish delivery vectors that IPs that have never sent
mail to Hotmail users start out with a negative reputation in
Hotmail's eyes.

Some info (admittedly, not too detailed, but it's all I could find handily):

Short version of what can be done:
- Ensure any host sending mail has working forward/reverse DNS.
- Start signing mail with Sender ID.
- Contact Hotmail here:
- Wait and hope for a response.

It's impacting a lot of folks right now, from what I can see. Hotmail
has been very slow to address (or even respond) in some instances. I
theorize that this is because they are receiving a lot of contact
about this issue, but certainly don't know that for sure.

Al Iverson