It is common for messages from certain IPs to be filtered based on the recommendations of Microsoft's SmartScreen filter, which is built around the technology of machine learning. SmartScreen's filters are trained to recognize what is and isn't spam, no specific details about what these filters specifically entail are known as this would render them useless.
SmartScreen's spam ratings are based on the reputation of the sender. One way to positively impact the reputation of your IP is to obtain SPF/Sender ID records. This technology allows SmartScreen to better track emails from your IP, weeding out spoofed messages. You can find additional information on creating SPF records at http://www.microsoft.com/senderid. Please confirm that your emails comply with MSN Hotmail's technical standards. This information can be found at: http://postmaster.live.com/Guidelines.aspx. You may also find additional information on common delivery questions at the Hotmail Postmaster Site found at: http://postmaster.msn.com/.
Hotmail has created the Smart Network Data Services program which helps legitimate email senders work with their customers and partners to reduce spam originating from their IP. Please visit http://postmaster.msn.com/snds/ for further information. This program allows a sender to monitor the 'health' of their IPs and user complaints. Hotmail also has a sender complaint feedback loop program Junk Email Reporting Program (JMRP). Enrollment in this, free of charge, program will benefit you as a sender as it will keep your e-mail lists updated and populated with interested MSN Hotmail Customers. Participation in this program will remove those MSN Hotmail Customers who do not want to receive e-mails from your company. If you are interested in joining this program please visit Http://support.msn.com/eform.aspx?pr...ail&ct=eformts. While using the SNDS tool, enrollment in the JMRP or having your IPs registered with Sender ID will not allow emails from your mail servers to bypass the filters, these are in place to help legitimate companies deliver their emails to Hotmail Customers.
Many legitimate mailers and marketers have qualified and joined Sender Score Certified Mail Program to improve mail deliverability and decrease email from being filtered to the Junk E-mail Folder. Sender Score is a third party program, administered by Return Path. The troubleshooting steps in this email are recommendations only, Microsoft makes no guarantees that following these steps will guarantee deliverability to MSN, Hotmail, or Live.com customers.
Suncoast Hosting support team can setup a SPF record for your domain, please contact our team via live chat or by submitting a ticket in the My Account area and ask them to setup a SPF record for your domain and they will let you know when this it has been done.
In recent times, the requirement to have DKIM and DMARC dns records setup has been implmented by Microsoft and other providers to help combat spam and malicious emails being sent. If you have a SPF record but do not have a DKIM and/or DMARC record it can cause your emails to not be delivered to Hotmail and Yahoo customers.