The question explores alternatives to Validity for Microsoft deliverability certification. The consensus is that while no direct certification guarantees inbox placement with Microsoft, several strategies and services can improve deliverability. The Certified Senders Alliance (CSA) is mentioned as a whitelist that can improve deliverability if its standards are met. ISIPP SuretyMail's 'Good Senders' list is used by some Microsoft filters. Actively using Microsoft's SNDS tool to monitor reputation, directly contacting Microsoft support, and implementing SPF, DKIM, and DMARC for email authentication are highlighted. Maintaining good sender reputation, warming up IPs, monitoring metrics, and avoiding blacklists are also crucial. It's important to understand that Microsoft uses a variety of signals for determining deliverability, not just certifications.