MS SMTP Server problems (incoming)

Before I installed Windows XP Pro SP1, I was running Windows 2K Pro along with Microsoft's SMTP mail server (for receiving mail). I used ColdFusion MX for sending mail. I have a few websites that run under the name "sweetness.dyndns.org" and as a curiosity, I decided to email myself. Well, it just so happened that I was actually able to receive mail. So I wrote a rather smooth program that filtered spammers out and life was grand. (Sidenote: I do not remember how I had SMTP set up to receive mail).

A few months later, I decided it was time to do a little cleaning up around the desktop, so I ended up installing a fresh copy of Windows XP Pro. SP1. After about 2 hours I had my server back up (IIS, Apache, CFusionMX 6.1, SMTP). Right off the bat I did an email test..waited...waited...checked inbox....nothing....waited....waited....checked all "mailroot" folders...nothing. Then finally I got something....an email in the Bad Mail folder. Well, to make a long story short, I have no idea where to go for information pertaining to my problem.

I have a few ideas of my own, as to why my domain name is not receiving email.

1) My ISP is blocking all incoming email to my domain (although there were actually two random emails in my inbox from some unknown location)

2) There is some configuration setting within the IIS Adminstration under the SMTP Server properties that is causing this to occur.


If anyone has any idea as to how my problem may be solved, or has a few internet resources that may be of help to me, please, respond as soon as possible. I have (well, make that HAD) an email service (still in beta mode) that I was going to use to allow people to have a free email address (BETA because of the dynamic IP address, along with sub-level domain name).

Regard,

Matt