Attic M365 FREE vs GreatHorn Mailbox Intelligence: Side-by-Side Comparison (2026)

Attic M365 FREE: Protects Microsoft 365 users from phishing attacks using fake login pages. built by Attic Security. Core capabilities include Real-time detection of fake Microsoft 365 login pages, Red alarm screen warning when accessing fraudulent pages, Authenticity seal display on official Microsoft 365 login pages..

GreatHorn Mailbox Intelligence: Email security tool empowering users to identify & report phishing threats. built by GreatHorn. Core capabilities include Visual sender and domain trustworthiness indicators, In-email banner notifications for suspicious messages, User-initiated phishing reporting capabilities..

Both serve the Anti-Phishing market but differ in approach, feature depth, and target audience.

Attic M365 FREE differentiates with Real-time detection of fake Microsoft 365 login pages, Red alarm screen warning when accessing fraudulent pages, Authenticity seal display on official Microsoft 365 login pages. GreatHorn Mailbox Intelligence differentiates with Visual sender and domain trustworthiness indicators, In-email banner notifications for suspicious messages, User-initiated phishing reporting capabilities.

Attic M365 FREE is developed by Attic Security. GreatHorn Mailbox Intelligence is developed by GreatHorn. Vendor maturity, funding stage, and team size can be important factors when evaluating long-term viability and support quality.

Attic M365 FREE integrates with Microsoft 365. GreatHorn Mailbox Intelligence integrates with Microsoft 365, Google Workspace. Check integration compatibility with your existing security stack before deciding.

Attic M365 FREE and GreatHorn Mailbox Intelligence serve similar Anti-Phishing use cases: both are Anti-Phishing tools. Review the feature comparison above to determine which fits your requirements.