• Monitor user complaints. Windows Live Hotmail also has a sender complaint feedback loop program called the Junk E-mail Reporting Program (JMRP). Enrollment in this free program will benefit you as a sender as it will keep your e-mail lists updated and populated with interested Windows Live Hotmail Customers. This program will help you to remove those Windows Live Hotmail Customers who do not want to receive e-mails from your company. If you are interested in joining this program, please visit see more http://support.msn.com/eform.aspx?productKey=edfsjmrpp&page=support_home_options_form_bye-mail&ct=eformts.
• Windows Live Hotmail has created the Smart Network Data Services program. This is a service that helps legitimate e-mail senders work with their customers and partners to reduce spam originating from their IP. To register, please go to http://postmaster.msn.com/snds/. This program allows a sender to monitor the 'health' of their IPs.

You can maintain your SPF records and use spam protection on your server as well. If you are running cPanel, you should be able to edit your Zone Records. To add an SPF record, i would recommend looking at the following site. It will assess your DNS Records, and provide suggestions of additional steps you may need to take.

Sender ID Framework SPF Record Wizard
This four-step wizard will guide you through the process of creating a new SPF record for your DNS domain. You should add this DNS record to your domain's DNS configuration. Note that you may need to manually edit the SPF record created by this wizard if you want to use some of the more advance features of the SPF format. For complete details please refer to the SPF record specification at http://www.microsoft.com/senderid.
Source: http://www.microsoft.com/mscorp/safety/content/technologies/senderid/wizard/

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