IP Address: 205.220.171.129 ⚠ Network Confounder

⚠ Network Confounder Detected: Proofpoint Email Security
Proofpoint network identifier

This page shows DMARC authentication failure data for this IP address. Learn more about this data.

Geolocation Information

Country:: US United States
Coordinates:: 37.751, -97.822

WHOIS Information

Network Name:: PROOF
CIDR:: 205.220.160.0/19
Owner:: Proofpoint, Inc.
Org ID:: PROOF
Address:: 925 W Maude Ave, Sunnyvale, CA 94085
Reverse DNS:: mx0a-0077b901.pphosted.com
Last updated: 2/5/2026

Analysis

This IP was first observed on September 25, 2024 and most recently on October 1, 2025. It has been associated with 12 failed authentication events affecting 14 messages, representing moderate activity. The IP belongs to PROOF (Proofpoint, Inc.), a network with activity associated with United States.

Failures Detected from this IP

Showing 1-12 of 12 failures, affecting 14 messages

Date ▼	Messages
10/1/2025	1
9/26/2025	2
9/24/2025	1
9/10/2025	1
9/3/2025	2
8/1/2025	1
7/17/2025	1
2/28/2025	1
2/26/2025	1
12/20/2024	1
12/11/2024	1
9/25/2024	1

External Reputation Lookups

Look up this IP in external threat intelligence and reputation databases (opens in new tab):

AbuseIPDB Cisco Talos Project Honey Pot GreyNoise VirusTotal Shodan Censys Spamhaus