After receiving a numerous amount of support tickets from you regarding email issues with non-delivery of emails, we finally figured out what was going on.
Apparently the previous owner of the ip address was a spammer and as we all know (or should) they like to move around from ip address to ip address to keep ahead of those trying to stop them from plying their wares.
As this cannot be avoided it becomes a painful experience when your host (us) has to try and convince the owners of the black list that we are indeed who we say we are and not anyone malicious.
After about 2 weeks of waiting for Microsoft to respond to our removal request they finally believed us that we were not intentionally using our server to send spam (unsolicited emails). Those of you who are using or planning to create and use a mailing list will now have to inform us that you are doing or intending to do so.
This is to make changes to your account allowing you to send optin only email to your mailing list. We have placed restrictions on the amount of mail being sent and the amount of double optin users allowed in your mailing lists. If you find that we are too restrictive you can contact us and ask for an increase in your settings. However, we will require written assurances from you that you will not create mailing lists without a double optin sign up feature in place. You are also required to follow the Can Spam policy and US Spam policies by law when sending email correspondence to either country. Also make sure you learn any other spam policies from other countries you send mail to.