Sh4mefulIP Address: 52.103.166.9 ⚠ IP Confounder
Covers 52.100-103.x.x outbound; PTR: *.outbound.protection.outlook.com
Differentiating between Office 365, including email protection services, and Azure (public cloud) when diagnosing incidents is challenging because they utilize shared Microsoft-owned IP ranges. Most of this is probably O365/Outlook or Defender protection breaking DKIM and SPF authentication. Disambiguation is a work-in-progress.
This page shows DMARC authentication failure data for this IP address. Learn more about this data.
Geolocation Information
- Country:
- GB United Kingdom
- Region:
- Wales
- City:
- Cardiff
- Coordinates:
- 51.4801, -3.1855
WHOIS Information
- Network Name:
- MSFT
- CIDR:
52.96.0.0/12, 52.112.0.0/14- Owner:
- Microsoft Corporation
- Org ID:
MSFT- Address:
- One Microsoft Way, Redmond, WA 98052
- Reverse DNS:
-
mail-ukwestazrln10221009.outbound.protection.outlook.com
Last updated: 2/5/2026
Analysis
This IP was first observed on September 13, 2024 and most recently on September 27, 2024. It has been associated with 2 failed authentication events affecting 2 messages, representing low but recurring activity. The IP belongs to MSFT (Microsoft Corporation), a network with activity associated with United Kingdom. 3 other IPs in the same /24 subnet (52.103.166.*) also appear in this dataset.
Network Topology
External Reputation Lookups
Look up this IP in external threat intelligence and reputation databases (opens in new tab):
Nearby IPs
Other IPs in the 52.103.166.0/24 range observed failing DMARC:
52.103.166.1 (2 failures), 52.103.166.10 (1 failure), 52.103.166.8 (1 failure)