The email-security buy walks a sequence. First you see the assets: MX, the Microsoft 365 or Google tenant, and the mailbox as a data store. Then you control inbound, gateway or API, so a lookalike domain hits a policy before the wire. Then you detect what already landed: pull-back, banners, OAuth grants, the archive. Then you prove the gateway miss can still be reversed. App-consent abuse is not even a message.
The shortlist: Proofpoint for enterprise policy depth, IRONSCALES for API speed and user-report triage, Material Security for OAuth and data-at-rest in the inbox, and FortiMail for hybrid and on-prem mail.
Native Microsoft or Google controls still do the commodity work. The products below cover the gap those miss.
On 17 Jul 2026 Proofpoint put Core Email Protection API into Threat Protection Workbench for Microsoft 365. That is a mailbox-after path from a vendor most shortlists still treat as inbound-gateway only. The phish that landed is the one the gateway missed. If you were skipping Proofpoint because you would not cut MX, that reason aged out in July.
Inbound-gateway versus mailbox-after. The gateway sees the message before the inbox. Mailbox-after pulls it back, banners it, or locks the archive once it is already there. Payload-free BEC is a mailbox-after problem. App-consent abuse is not even a message. Pick the door before you change MX.
Proofpoint
Proofpoint combines predelivery controls with post-delivery detection and remediation across phishing, BEC, ransomware, and impersonation. Deploy it as a cloud service or a gateway. The company states more than 80 of the Fortune 100 and over 10,000 large enterprises. Targeted Attack Protection rewrites links at click time and sandboxes files. Impostor detection uses identity and behavior, not payload inspection alone. User-reported phish can be clustered and pulled back across mailboxes.
Hornetsecurity, acquired for $1.8 billion and closed in December 2025, now runs as the MSP and SMB unit. 365 Total Protection is the multi-tenant package (backup, compliance, awareness) for 12,000-plus MSPs and 125,000 customers. In 2026 Proofpoint also extended the platform story to AI agents alongside people and data. Two product lines now serve different segments. Write which one the quote covers.
Best for: Large enterprises that need granular policy, layered URL and attachment analysis, and quarantine workflows across messy mail flow.
Key Features:
- Click-time URL rewriting and sandbox analysis for links and files.
- BEC and impostor detection on identity and behavioral signals.
- Automated user-report triage with post-delivery mailbox remediation.
- Hornetsecurity path for MSPs and smaller tenants that will not buy enterprise Proofpoint.
Why we like it: Depth of policy is what lets a large team tune without breaking mail. The Hornetsecurity close also gives smaller buyers a real multi-tenant door that did not exist when Proofpoint was enterprise-only. The July API path is the other door: mailbox-after without an MX cutover. Write which door the quote covers. Two product lines plus an API SKU is a naming mess you can solve on the PO.
Notable Limitations:
- Admin complexity and tuning effort are the consistent review themes.
- Cost is premium. The enterprise SKU is not sized for a 50-mailbox shop.
- Support response during heavy incidents varies in public reviews. Ask for the escalation path.
Pricing: Quote. Contact Proofpoint on mailbox count and modules, or a Hornetsecurity partner for MSP packaging. No first-party list rate.
IRONSCALES
IRONSCALES is API-based email security: adaptive detection, mailbox-level remediation, phishing simulation, and user engagement. The AWS listing puts the estate at more than 15,000 organizations and a network of 20,000-plus analysts. Setup is a Microsoft 365 or Google Workspace consent, not an MX cutover. Most customers, the listing says, spend under 12 minutes a day remediating.
Winter 2026 added three agents: Red Teaming (reconnaissance), Phishing SOC (triage and response), and Phishing Simulation (continuous, per-employee). Complete Protect adds account-takeover detection, Microsoft Teams protection (including deepfake defense), outbound encryption, and awareness training. QR-code (quishing) detection is on the current product. There is no gateway SKU. Hybrid or on-prem mail needs a different tool.
Best for: Cloud-mailbox teams that want API deploy, automated cleanup, and a user-report loop that actually trains the model.
Key Features:
- Mailbox-level pull of phishing, BEC, and ATO messages across affected inboxes.
- Red team, SOC, and simulation agents from the Winter 2026 release.
- Themis Co-Pilot as a gen-AI inbox assistant (separate AWS dimension).
- Dynamic banners and campaign clustering so one report cleans a wave.
Why we like it: API setup is minutes. The 2026 agents target the two jobs that eat analyst time: triage and writing the next simulation.
Notable Limitations:
- API-only. No SEG for hybrid or regulated on-prem flows.
- Reviewers still note false positives and feature gaps on lower tiers.
- Modules stack. Price Complete if ATO and Teams are in scope.
Pricing: On the AWS Marketplace listing, 12-month dimensions at a 50-user minimum: Starter (phishing simulation) $0, IRONSCALES Protect $3,600, Email Protect $4,200, Complete Protect $6,000. Add-ons at $1,200 each: Security Training, Incident Management, Account Takeover Protection, Themis Co-Pilot. That is $6 / $7 / $10 per user per month at the 50-seat floor for the three paid bundles. The 50-user minimum is the real floor. A 20-mailbox shop is not buying that listing at list.
Does Email Protect at the 50-seat floor include mailbox pull-back?
The AWS listing does not say whether Email Protect is inbound only or includes post-delivery remediation. Complete Protect is the bundle that names ATO and Teams.
Material Security
Material Security is detection and response for Google Workspace and Microsoft 365 that treats the mailbox as a data store. Post-delivery email security sits next to file sharing, OAuth grants, and account-takeover controls. Shared and dedicated (single-tenant) deployments are both offered.
The pricing page is public. Essentials is $4 per user per month billed annually, plus a Shared Drive size fee (minimum annual covers up to 1 TB). It includes inbound threat detection, an automated agent for user-reported phish, an OAuth app inventory, Shared Drive metadata, and workspace posture. Advanced is $6 and adds agentic investigation and remediation of OAuth grants, sensitive content in drives and email, and stronger identity detections. ATO Resilience is +$3 on a package, or $5 stand-alone: message-level MFA on historical sensitive mail and on password-reset / magic-link messages, so a stolen session does not become a searchable archive.
Best for: Teams whose real incident is someone already in the mailbox.
Key Features:
- Post-delivery detection and flexible remediations (banner, speedbump, spam, delete).
- OAuth inventory on Essentials. Agentic classify-and-revoke on Advanced.
- Sensitive content and sharing controls on email and Shared Drives (Advanced).
- ATO Resilience: message-level locks on the mail an attacker would read first.
Why we like it: Every other tool here asks whether the message is malicious. Material also asks what the attacker reaches if they get in. App-consent abuse grants durable inbox access without a phish. No inbound filter sees that.
Notable Limitations:
- Navigation is dense. Budget policy time per business unit.
- Shared Drive storage is a second meter. Size it on the discovery call.
- Smaller public review base than Proofpoint or IRONSCALES.
Pricing: Essentials $4 / user / month (annual). Advanced $6. ATO Resilience +$3 or $5 stand-alone. Volume discounts and dedicated tenancy are sales conversations.
FortiMail
FortiMail Email and Workspace Security is two products under one portfolio. The secure email gateway still ships as a physical appliance, a VM, or FortiMail Cloud. FortiMail Workspace Security is the former Perception Point ICES layer for cloud mailboxes, browsers, and collaboration apps. FortiGuard intelligence, DLP, identity-based encryption, and FortiSandbox sit on the gateway side. Fabric integration means an indicator seen in mail can inform FortiGate without a SIEM project.
Gartner placed Fortinet as a Challenger in the 2025 Magic Quadrant for Email Security. That is a useful reminder: you buy this for deployment flexibility and Fabric.
Best for: Hybrid and on-prem environments, regulated isolation, and existing Fortinet estates that want email in the same policy domain as the firewall.
Key Features:
- Anti-spam, phishing, malware, and ransomware with outbreak detection.
- DLP and encryption mapped to SOX, GLBA, HIPAA, and PCI DSS.
- FortiMail Cloud scanning for Microsoft 365 and Google Workspace, with or without the gateway.
- Workspace Security for browser and collaboration beyond the inbox.
Why we like it: The API-native tools on this page cannot serve an isolated mail flow. FortiMail can. Fabric correlation is the bonus if FortiGate is already the edge.
Notable Limitations:
- Learning curve, dated UI, and more tuning than newer API tools show up in reviews.
- Cloud feature parity has lagged the appliance on some options. Check the SKU.
- SEG and ICES names overlap. Scope the quote to gateway, Workspace Security, or both.
Pricing: BYOL and PAYG images on public cloud, appliance and perpetual licences through partners. Quote.
What we left out
Abnormal if behavioral BEC on Microsoft 365 is the only hole and you will pay enterprise. Mimecast if the incumbent gateway is already theirs. Microsoft Defender for Office 365 / Google Workspace native as the baseline. KnowBe4 is training.
Questions before you change MX or grant an API
Do you need a gateway at all?
Pure Microsoft 365 or Workspace: IRONSCALES or Material. Hybrid, internal mail, or an isolated network: Proofpoint or FortiMail. Most migrations run both for a while. That is fine.
What happens after the message lands?
Payload-free BEC routinely passes inbound. If pull-back is manual search-and-delete, you do not have post-delivery.
Can it see OAuth?
Material inventories grants on Essentials and remediates them on Advanced. The others are message tools. Pair them with identity governance if app-consent is in scope.
