arc authentication

The arc authentication tag covers Microsoft 365 email security discussions involving inline inspection, third-party security services, and the handling of identity and authentication signals as messages pass through multiple systems. The available content examines whether routing mail through additional inspection layers provides meaningful protection or creates operational complexity. It also considers how Microsoft Defender verdicts can be preserved and trusted across each hop, along with the challenges of diagnosing failures when several security control planes interact. This tag is relevant to administrators evaluating mail-flow architecture, authentication continuity, security verdicts, and troubleshooting in sophisticated cloud email environments.