Microsoft 365 Email Security: Close the gap Defender leaves open
Defender blocks inbound threats. MailBreach monitors the configuration layer — hidden forwarding rules, suspicious inbox filters, and tenant posture drift — where post-compromise attacks live.
Cancel anytime · Admin consent flow · Revoke access anytime
What MailBreach does for you
Scans every M365 mailbox automatically
Connect via admin consent OAuth. We enumerate all users and scan every inbox rule, forwarding setting, and mailbox configuration. No agents, no software installs.
Monitors what Defender misses
Defender excels at email content inspection. MailBreach scans the configuration layer — the rules attackers create after gaining access — which sits below Defender's visibility.
Compliance evidence built in
Weekly evidence reports with full audit trails. Document your security posture for SOC 2 audits, cyber insurance underwriters, and internal compliance reviews.
Built for trust
Ready to find what's hiding in your mailboxes?
Connect your tenant and get your first scan in under 15 minutes.
Cancel anytime · Admin consent flow · Revoke access anytime
Common questions
What Microsoft 365 permissions do you need?
We request minimum required permissions: MailboxSettings.ReadWrite and Mail.Read (for rule metadata only, never email content), plus User.Read.All for directory enumeration. Admin consent via standard Microsoft OAuth flow.
Does MailBreach replace Microsoft Defender?
No — it complements it. Defender handles inbound threats brilliantly. MailBreach adds visibility into post-compromise configuration abuse, which is a different threat surface entirely.
How does auto-remediation work in M365?
We use the Graph API to disable or delete inbox rules depending on severity and your settings. Every action is captured with a before-snapshot, verified after execution, and logged with full audit details.
Can I scope scans to specific users or groups?
By default we scan all users — that's the safest approach since attackers target any mailbox. Scoped remediation (applying fixes only to selected groups) is on our near-term roadmap.