It is against Outlook.com policy to send mail from a machine which is an open proxy server, and it will be blocked from accessing some or all of Outlook.com servers as long as it remains in that state.
Deliverability to Outlook.com is based on your reputation. The Outlook.com Smart Network Data Services (SNDS) gives you the data you need to understand and improve your reputation at Outlook.com.
The goal for Outlook.com is to offer a comprehensive and usable email service that helps detect and protect users from junk email, fraudulent email threats (phishing) and viruses.
Senders attempting to send email to Outlook.com users should ensure they fully understand and are following the guidance on this page to help in this effort and to help avoid potential deliverability issues.
If you are an Outlook.com user looking for support with your account, please visit our end user support page. If you are experiencing problems delivering email to Outlook.com please first ensure that you are following all of the requirements found on our Policies and Guidelines page.
Therefore, we have built some services to help ISPs gain a good understanding of the type of traffic originating from their networks and reaching Outlook.com customers.
