Sh4mefulIP Address: 23.103.209.49 ⚠ IP Confounder
GCC/Commercial outbound; PTR: *.outbound.protection.office365.us
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:
- US United States
- Coordinates:
- 37.751, -97.822
WHOIS Information
- Network Name:
- MSFT
- CIDR:
23.96.0.0/13- Owner:
- Microsoft Corporation
- Org ID:
MSFT- Address:
- One Microsoft Way, Redmond, WA 98052
- Reverse DNS:
-
mail-cy1usg02on0049.outbound.protection.office365.us
Last updated: 4/15/2026
Analysis
This IP was observed on a single date: April 10, 2026. It has been associated with 1 failed authentication event affecting 1 message — a single isolated event. The IP belongs to MSFT (Microsoft Corporation), a network with activity associated with United States. 8 other IPs in the same /24 subnet (23.103.209.*) 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 23.103.209.0/24 range observed failing DMARC:
23.103.209.47 (4 failures), 23.103.209.88 (3 failures), 23.103.209.55 (2 failures), 23.103.209.79 (2 failures), 23.103.209.60 (2 failures), 23.103.209.56 (1 failure), 23.103.209.44 (1 failure), 23.103.209.52 (1 failure)