Email sent from server with rDNS & SPF being blocked by Hotmail

Your title says your email is being blocked by hotmail.com but in one of your comments to Stony's answer you state that your SMTP log shows "RCPT=OK" and "RECV=OK" when sending email to hotmail.com. That in and of itself should be telling you that your email is not being blocked. It's being accepted by hotmail.com and is most likely being filtered after being accepted. there's a difference between an email being blocked/rejected and being filtered after being accepted.

You state that you can't telnet to port 25 of mail.hotmail.com. That's because mail.hotmail.com is not an MX for hotmail.com. A quick nslookup shows the following MX records for hotmail.com: mx1.hotmail.com, mx2.hotmail.com, mx3.hotmail.com, and mx4.hotmail.com.

You state that you can't ping hotmail.com but you can ping gmail.com. It's irrelevant whether or not you can ping hotmail.com or any other server, name, web site, etc. The ping tool doesn't test the availability of a service (web, email, etc). The fact that you can't ping hotmail.com only means that the hosts that hotmail.com resolve to don't respond to pings or that a firewall is blocking those pings. It's totally irrelevant to the problem. In addition, pinging hotmail.com has nothing to do with the MX records for hotmail.com. Hotmail.com is the domain name and pinging hotmail.com is pinging the A records configured for that domain name. When you ping gmail.com you're pinging the A record for that domain name, you're not pinging the MX records for gmail.com.

Have a look at the Hotmail Postmaster page here to see if there's anything you need to look in to:

http://mail.live.com/mail/troubleshooting.aspx

My issue was fixed by contacting Microsoft and they had to manually remove a block on my IP. Once the block was removed emails from my server were reaching Hotmail, but going directly to junk mail.

I have created a separate question to try and resolve the junk mail problem: Hotmail marking messages as junk