I've recently moved all my personal email to Hotmail and I'm getting responses from Spamcop to say that the email server I'm using is being blocked as its been reported as sending spam:

 - These recipients of your message have been processed by the mail server:

*** Email address is removed for privacy ***; Failed; 5.3.0 (other or undefined mail system status)

    Remote MTA mail.02.net: network error

 - SMTP protocol diagnostic: 550 mail not accepted from blacklisted IP address, see: http://spamcop.net/bl.shtml [65.20.0.50]

I realise that the server may be off the blacklist in 24 hours or so, but its very inconvenient.  How can I escalate this and what is Microsoft doing to prevent this?

Thanks