Sender Policy Framework (SPF) is another authentication tool to prevent spamming and spoofing. SPF allows senders to define which IP's are allowed to send email for a particular domain.
SPF Adoption Over Time
- Feb 2025: 99.96%
- Jan 2025: 99.91.%
- Dec 2024: 99.98%
- Nov 2024: 99.93%
- Oct 2024: 99.87%
- Sept 2024: 99.72%
- Aug 2024: 99.78%
- July 2024: 99.83%
- June 2024: 99.93%
- May 2024: 99.98%
- Apr 2024: 99.96%
- Mar 2024: 99.98%
- Feb 2024: 99.98%
- Jan 2024: 99.97%
- Dec 2023: 99.81%
- Nov 2023: 99.85%
- Oct 2023: 99.8%
- Sept 2023: 99.65%
- Aug 2023: 99.11%
- July 2023: 98.57%
- June 2023: 95.71%
- May 2023: 98.16%
- Apr 2023: 97.51%
- Mar 2023: 94.38%
- Feb 2023: 92.33%
- Jan 2023: 93.81%
- Dec 2022: 97.56%
- Nov 2022: 98.83%
- Oct 2022: 99.17
- Sept 2022: 99.21%
- Aug 2022: 99.39%
- July 2022: 99.31%
- June 2022: 99.0%
- May 2022: 98.96%
- Apr 2022: 99.07%
- Mar 2022: 98.85%
- Feb 2022: 98.22%
- Jan 2022: 98.21%
- Dec 2021: 98.32%
- Nov 2021: 98.47%
- Oct 2021: 98.66%
- Sept 2021: 96.43%
- Aug 2021: 98.15%
- July 2021: 97.74%
- June 2021: 96.12%
- May 2021: 98.13%
- Apr 2021: 96.67%
- Mar 2021: 95.52%
- Feb 2021: 95.93%
- Jan 2021: 97.05%
- Dec 2020: 95.89%
- Nov 2020: 93.07%
- Oct 2020: 0%
- Sep 2020: 0%
- Aug 2020: 0%
- Jul 2020: 0%
- Jun 2020: 0%