IP Address: 148.163.133.148 ⚠ 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
Region:: California
Coordinates:: 34.0544, -118.244

WHOIS Information

Network Name:: PROOFPOINT-NET-NORTH-AMERICA
CIDR:: 148.163.128.0/19
Owner:: Proofpoint, Inc.
Org ID:: PROOF
Address:: 925 W Maude Ave, Sunnyvale, CA 94085
Reverse DNS:: mx0a-00390501.pphosted.com
Last updated: 2/5/2026

Analysis

This IP was first observed on July 11, 2025 and most recently on July 23, 2025. It has been associated with 2 failed authentication events affecting 2 messages, representing low but recurring activity. The IP belongs to PROOFPOINT-NET-NORTH-AMERICA (Proofpoint, Inc.), a network with activity associated with United States. One other IP in the same /24 subnet (148.163.133.*) also appears in this dataset.

Failures Detected from this IP

Showing 1-2 of 2 failures, affecting 2 messages

Date ▼	Messages
7/23/2025	1
7/11/2025	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

Nearby IPs

Other IPs in the 148.163.133.0/24 range observed failing DMARC:

148.163.133.153 (18 failures)