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Mailbox Providers (MBPs)

The "harbor masters" (or "ISPs"). These are the "big 4" companies that provide inboxes to users: Gmail (Google), Outlook (Microsoft), Yahoo, and Apple. Their 'rules' are the 'laws' of the email sea.

9 questions in this topic

Questions about Mailbox Providers (MBPs)

What do Gmail, Yahoo, and Outlook actually do? How do mailbox providers decide inbox vs spam? What are smaller mailbox providers (ProtonMail, Zoho, GMX, Yandex, etc.)? How do regional MBPs differ from global ones? What role do postmaster tools play in the MBP ecosystem? How do MBPs share spam data (industry collaboration)? How do MBPs cooperate with law enforcement? How do MBPs work with blocklists and anti-abuse orgs? What is a postmaster contact form and when to use it?