Sh4mefulNetwork: SENDGRID-149-72-0-0-16
Twilio SendGrid is a cloud-based Email Service Provider (ESP), or Mail Transfer Agent (MTA). It operates as a high-volume, cloud-based SMTP service to send, receive, and relay both transactional and marketing emails. These signals could be indicative of a failure during legitimate sends (through Sendgrid), or could be signal of a spam/spoof attempt using their service which is common enough we're not treating this as a confounder.
This page shows DMARC authentication failures originating from the SENDGRID-149-72-0-0-16 network. Learn more about this data.
Analysis
This network has contributed 5 unique IP addresses across 38 failed authentication events, accounting for 1,490 messages. Activity spans from March 9, 2024 to January 14, 2026, with peak volume in March 2024 (664 events). The top countries by failure volume are United States (100%). The most active source IPs from this network include 149.72.115.133 (297 failures), 149.72.61.226 (267 failures), 149.72.114.91 (266 failures). A single IP dominates activity from SENDGRID-149-72-0-0-16 (Twilio), a email delivery service,, suggesting a concentrated or persistent source rather than distributed infrastructure.
Failures Detected from this Network
Showing 1-38 of 38 failures, affecting 1,490 messages| Date ▼ | Source IP | Country | Messages |
|---|---|---|---|
| 1/14/2026 | US | 1 | |
| 9/6/2025 | US | 1 | |
| 5/23/2025 | US | 5 | |
| 5/23/2025 | US | 4 | |
| 5/23/2025 | US | 3 | |
| 4/11/2025 | US | 1 | |
| 12/20/2024 | US | 6 | |
| 12/20/2024 | US | 6 | |
| 12/20/2024 | US | 5 | |
| 12/19/2024 | US | 6 | |
| 12/19/2024 | US | 6 | |
| 12/19/2024 | US | 4 | |
| 12/17/2024 | US | 1 | |
| 12/11/2024 | US | 23 | |
| 12/11/2024 | US | 31 | |
| 12/11/2024 | US | 22 | |
| 12/9/2024 | US | 1 | |
| 11/21/2024 | US | 1 | |
| 11/20/2024 | US | 10 | |
| 11/20/2024 | US | 12 | |
| 11/20/2024 | US | 7 | |
| 11/11/2024 | US | 2 | |
| 11/11/2024 | US | 2 | |
| 11/8/2024 | US | 1 | |
| 10/22/2024 | US | 1 | |
| 10/22/2024 | US | 2 | |
| 9/26/2024 | US | 2 | |
| 9/26/2024 | US | 1 | |
| 9/25/2024 | US | 1 | |
| 9/17/2024 | US | 2 | |
| 5/10/2024 | US | 2 | |
| 3/13/2024 | US | 259 | |
| 3/13/2024 | US | 313 | |
| 3/13/2024 | US | 284 | |
| 3/12/2024 | US | 149 | |
| 3/12/2024 | US | 143 | |
| 3/12/2024 | US | 169 | |
| 3/9/2024 | US | 1 |