IP Address: 20.245.215.64 ⚠ IP Confounder

⚠ IP Confounder Detected: Trend Micro Cloud App Security (TMCAS) - Part of Trend Vision One(tm), Cloud Email and Collaboration Protection. An API-based security solution (for email and more), that protects MS Office 365, Google Workspace, Box and Dropbox. Phishing, ransomware, and BEC/DLP.
Seems to break DKIM and SPF, thus DMARC.

ℹ️ Network Annotation: Microsoft Network (365 vs Azure)

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.

Last updated: 1/29/2026

About this Data

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The data here is from DMARC analysis for domains I administer, drawn from a larger dataset (comprising millions of authentication records and messages). These entries are from email attempts that failed both SPF and DKIM (and there are often alignment issues - hidden here). In many cases, these failures indicate unauthorized use of the domain name, and are commonly associated with spoofing, phishing, or other abusive mail activity.

(More)

Geolocation Information

Country:: US United States
Region:: California
City:: San Jose
Coordinates:: 37.3388, -121.8916

WHOIS Information

Network Name:: MSFT
CIDR:: 20.192.0.0/10
Reverse DNS:: inpost.tmcas.trendmicro.com
Last updated: 2/5/2026

Failures Detected from this IP

Showing 1-2 of 2 (failures, affecting 2 messages)

Date ▲	Messages
9/18/2024	1
6/28/2025	1