Messaging Gateway

My domain's IP (ccgenie.com / 46.105.127.213) has been black-listed by Symantec three times during the last month, preventing my application from sending emails to hotmail.com and live.com. Every time I was able to un-list using the IP reputation tool at http://ipremoval.sms.symantec.com/lookup/ but nevertheless my service was disrupted for several hours.

I have run my domain IP and email headers through checkers like http://mxtoolbox.com/ and http://www.dnsstuff.com/ and found no problems. My website runs a perfectly legitimate business application that only sends a few dozens emails per day, and only to opt-in users.

Is there a way I can prevent this from happening again?

Thanks!

I am having this same issue even after my website has been Verisign'd.

Who are we supposed to contact to fix an issue like this? Approaching via Microsoft has not resulted in any form of response.

http://85.10.206.116/

So you have the connection classification enabled under the Reputation tab.  If so and if this is what is blacklisting your IP try adding your IP  to the good senders list.