Problems sending emails to Hotmail adresses

[argusdt]

I am now no longer able to send emails to Hotmail addresses via Outlook 3. They are bounced back with the following message:

550 SC-001 (SNT0-MC4-F21) Unfortunately, messages from 81.169.146.164
       weren't sent. Please contact your Internet service provider
       since part of their network is on our block list. You can also
       refer your provider to http://mail.live.com/mail/troubleshooting.aspx#errors

However, I can send messages via Outlook through my own Hotmail account.

Any help greatly appreciated.

[kimura]

Try sending emails from other location other than your current connection like your office or your friend's house perhaps. I believe your IP was blocked.

Try this. Go to whatismyip.com, take note of you public IP, then enter it in http://www.spamhaus.org/lookup/. Post the results here. 

[argusdt]

Results from Spamhous are as follows.

109.151.30.225 is not listed in the SBL

109.151.30.225 is listed in the PBL, in the following records:

• PBL818031

109.151.30.225 is not listed in the XBL

I have tried all the recommended solutions with no luck!