Microsoft (Outlook.com and Hotmail) overview

Hotmail was one of the first web-based email services, which launched in 1996. The name Hotmail was created after HTML, or HoTMaiL. It's one of the most popular domains in the world and dominates the Brazilian, Australian, and European markets for email providers. Microsoft has established offices throughout the world to support its email infrastructure as well as to gain needed insights to tailor their tools and services to their diverse set of global users.

In 2013, Microsoft rebranded Hotmail and Windows Live Mail to Outlook.com.

Here are some key Microsoft statistics and information:

• Active users: Over 400 million
• Inbound emails that reach the inbox on average: 30% to 35%

In 2016, Microsoft merged their Office 365 platform with its other email platforms. Since 2017, all Microsoft email operates on one consolidated platform.

Infrastructure

Validity partnership with Microsoft

In partnership with Validity, Microsoft uses the Validity Certification allowlist to give preferential treatment for Certified senders. Microsoft sends volume and complaint data to Validity for use by Certified senders.

Validity Certification gives senders a high probability of getting their email delivered directly to subscriber inboxes. However, Certified senders may see issues with email delivered to the junk folder at Outlook.com if complaint rates are high.

Public monitoring services and escalation

Outlook.com offers services to help senders gain a good understanding of the type of traffic originating from their networks and reaching Outlook.com customers. Senders can use this data to help stop abusive activity, such as junk mail and phishing, in order to proactively manage sending reputation.

• Junk Mail Reporting Program (JMRP): Outlook.com's JMRP provides reports for email marked as junk or phishing by Outlook.com users. 
  • Microsoft records a complaint when the subscriber clicks on the 'this is spam' button or if the subscriber moves the email directly to the spam or junk folder. 
• Smart Network Data Services (SNDS): SNDS is a free service that provides high-level insight on how users rate the email they receive and the health of a sender's IP space. To receive complaint feedback through SNDS, senders should enroll at the Junk Mail Reporting Program (JMRP). Senders typically start receiving complaint feedback within SNDS in as little as 72 hours.
• Microsoft Support: Senders in compliance with Microsoft's sending guidelines and encountering deliverability problems can submit a support request for help with troubleshooting.