Q1 2025 Postmastery's Email Delivery Benchmark

Fifth Global Email Delivery Benchmark Report Summary

This quarterly report evaluates email delivery performance from January to March 2025, with comparisons to the previous Q4 2024 assessment.

The dataset has been expanded further, providing an even clearer snapshot of MBP email delivery performance. This benchmark offers a valuable baseline for senders to compare and enhance their email delivery metrics. Postmastery commits to releasing these benchmarks regularly, with the next report anticipated at the beginning of Q3 2025.

General Trends in Delivery Rates

• Google improved delivery slightly from 99.39%
  to 99.42%.
• Yahoo continued its positive trajectory, nudging up from
  99.78% to 99.82%.
• Outlook experienced a minor drop (99.89% > 99.86%) and
  a decline in average delivery time (from 8m 02s to 5m 56s).
• Mimecast and Proofpoint both continue to struggle with low
  delivery efficiency.

Key Recommendations

• Authenticate everything: SPF, DKIM, and DMARC are no
  longer optional.
• Monitor sending patterns: Spikes in volume, even from
  authenticated domains, can trigger temporary blocks or rate limits.
• Improve list hygiene: Many bounces are still due to disabled
  or over-quota inboxes.