What We Measure

Our probes break email delivery into clear stages so latency and reliability can be diagnosed accurately, not guessed.

Generation to Acceptance: Time from message creation/submission to SMTP acceptance by recipient infrastructure.
Acceptance to Inbox: Time from SMTP acceptance to mailbox placement (inbox/spam classification windows).
End-to-End Transit: Total elapsed time from message generation to observable mailbox arrival.
Delivery Outcomes: Success, temporary deferrals, permanent failures, and provider-specific error categories.
Regional & Provider Patterns: Comparative behavior across mailbox providers and regions under consistent probe methods.