The TL;DR
Where Do SEGs and Cloud-Native Email Security Each Shine - and Struggle?
When Does a Secure Email Gateway Still Make Sense and When Doesn't It?
Strengths: high-volume pre-delivery filtering for spam and known indicators, mature policies, and reputation checks.
Gaps: limited visibility into post-delivery behavior (forwarding rules, internal mail, lateral movement), little context across apps (email ↔ Drive), and no tenant-native ability to pull messages or reverse changes once delivered.
When Does Cloud-Native Email Security Win Over a Traditional SEG?
Strengths: sees what happens inside Workspace, correlates identity + behavior + content, and can remediate after delivery (pull messages, kill malicious forwarders, tighten file shares triggered by email workflows).
Gaps: relies on robust API access and tuned detections; best when paired with strong pre-delivery filtering to keep commodity noise down.
What to enable in Google Workspace (so both sides work together)
Start with the controls you already own:
- Gmail → Advanced phishing & malware protection. Turn it on and scope stricter settings to high-risk org units (Finance, HR, AP). This reduces commodity noise and flags suspicious patterns early.
- Gmail → Security Sandbox. Detonates risky attachments in isolation before users interact with them. Enable for targeted OUs first if you’re cautious.
- DMARC. Publish a DMARC policy and move from p=none to quarantine and ultimately reject as you gain confidence from aggregate reports. This blunts spoofing and aligns with supplier-fraud prevention.
- Context-Aware Access (CAA). Limit download/print/copy for viewers/commenters on unmanaged or noncompliant devices and tighten access by device posture or location. This turns a successful phish into a smaller incident.
With that foundation, add a cloud-native, in-tenant layer that watches for post-delivery signals (VIP/payment lures, unusual reply-to behavior, suspicious mailbox rules, impossible-travel logins) and auto-remediates: pull delivered messages, disable forwarders, and fix risky Drive shares created via email workflows.
Decision framework for 2025 (practical, not dogmatic)
Ask three questions:
- What’s your top loss scenario? If it’s still spam and known-bad malware, a tuned SEG + Gmail native controls might be enough. If it’s BEC/vendor fraud or internal misuse, you need post-delivery detection and remediation in-tenant.
- Where does your team spend time? If analysts chase inbox reports and manual pulls, moving those actions into an automated, tenant-native workflow returns hours per week and shrinks mean time to remediate (MTTR).
- Can you show outcomes? Track time-to-pull, malicious forwarders neutralized, Drive exposures closed, and wire attempts prevented. Tie improvements to IBM/IC3 benchmarks to communicate impact in dollars.
What “good” looks like in production
A healthy posture in 2025 keeps the SEG to block the obvious and lowers the noise floor for analysts. Inside Workspace, cloud-native controls watch behavior as it unfolds and fix issues automatically—not just alert. Security reviews focus on tuning policies and exceptions, not chasing tickets. Users still move quickly, but dangerous actions face just-in-time friction (sandboxing, DLP warnings, CAA restrictions), and the riskiest flows auto-roll back without a helpdesk thread.
Connect with Material Security
If you’re keeping your SEG, Material Security adds the cloud-native, post-delivery layer you’re missing. Inside Google Workspace, Material correlates identity, content, and behavior to catch BEC and account misuse; then it remediates automatically by pulling messages, disabling malicious forwarding rules, and tightening risky Drive shares that started from email workflows. The outcome is fewer false positives, faster MTTR, and clearer evidence that risk—and cost exposure—are going down. See Material Security in action today.
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