How does Microsoft (Outlook, Hotmail) determine placement?

Microsoft (Outlook/Hotmail) uses SmartScreen and proprietary filtering:

• IP reputation: Heavily weighted. New or low-reputation IPs face scrutiny.
• Authentication: SPF, DKIM, DMARC evaluation.
• Complaint rates: Feedback loop data influences filtering decisions.
• Content filtering: SmartScreen analyzes message characteristics.

Sender certification: Programs like Return Path Certification (now Validity) can improve standing.

Microsoft tends to be more IP-focused than Gmail's engagement-centric approach. New senders often face warming challenges.

Microsoft's port values established trading relationships. New ships undergo thorough inspection.