Email server rejected by Microsoft

Microsoft Just Killed Self-Hosted Email for Another 200,000 People

Zen Internet’s 200,000 users just found out their emails to Outlook and Hotmail were silently rejected — not because of spam, but because Microsoft decided their IP block was ’not eligible for mitigation.’ If you run a self-hosted mail server, this is your future too. Here’s what’s actually happening and what to do about it.

March 28, 2026 · 7 min · 1408 words · Manuel