Best email security solutions for MSPs in 2026: a buyer's guide

For MSPs evaluating email security in 2026, the right platform must do three things at once: detect AI-driven phishing and business email compromise (BEC), scale across many client tenants from a single console, and integrate with the rest of the security stack so analysts are not jumping between tools. Native Microsoft 365 protection alone is not enough. Below is a side-by-side comparison of six platforms MSPs commonly evaluate, followed by deeper sections on each.

Bottom line: if you already deliver backup, recovery or endpoint protection to clients, an integrated platform reduces tool sprawl and analyst context switching. If email security is your only managed service, an email-only specialist may be a better fit. Read on for the criteria, then the vendor sections.

Email is still the primary entry point for attackers, and the volume keeps climbing.

For an MSP, those numbers translate to one thing: the inbox is the busiest threat surface in every client environment you manage. Native Microsoft 365 and Google Workspace protections catch the easy stuff. They miss the rest, especially AI-generated phishing and payload-less BEC that has no malicious link or attachment to scan.

A dedicated email security platform sits in front of, alongside, or after the native mailbox protection and adds the AI-driven detection, sandboxing, URL rewriting and behavioral analysis that catches what native tools miss. For MSPs, the platform also has to scale across tenants, support MSP-friendly billing, and ideally fold into the rest of the security stack.

Three attack patterns have moved from the margins to the mainstream in the past 12 months, and each one breaks a specific assumption that older email security platforms were built on.

AI-generated phishing has closed the quality gap. A 2024 academic study found AI-generated spear phishing emails achieved a 54% click-through rate, matching the performance of human-crafted attacks at a fraction of the cost. The familiar tells (broken grammar, awkward phrasing) are gone. Static content rules tuned to those tells now miss the message entirely.

QR code phishing bypasses text-based filters by design. The Anti-Phishing Working Group tracked a 400% increase in image-based phishing heading into 2025. The malicious URL lives inside a pixel matrix, not in clickable text, so a gateway parsing message bodies for known-bad domains never sees it. The user scans the code on a phone, which moves the attack from a managed desktop to an unmanaged mobile device. Detection requires image-aware inspection, which not every platform performs.

ClickFix and FileFix attacks weaponize the user's own clipboard. Acronis TRU researchers documented a sophisticated FileFix campaign in September 2025 that combined a multilingual phishing site, anti-analysis obfuscation and steganography (malicious PowerShell hidden inside JPG images). These attacks do not contain a malicious attachment or a flagged URL. The phishing site instructs the user to paste content into File Explorer or PowerShell, and the user does the work the malware would normally do.

The common theme: detection now has to be behavioural and contextual, not signature-based. A platform that has not meaningfully updated its detection model in the past 18 months is exposing your clients to threats that were not a category when the platform was last architected.

This is not a ranked list with scores. Vendor environments and client portfolios vary too much for a universal ranking to be useful. Instead we evaluated each platform against six MSP-specific criteria.

Vendor sections below follow a consistent structure: overview, ideal use case, differentiators, strengths, limitations, pricing guidance, and recommendation.

Summary: Best for MSPs that want email security unified with backup, EDR, RMM and security awareness training in a single multitenant platform.

Acronis Email Security is an add-on to Acronis Cyber Protect Cloud, the platform 21,000-plus service providers use to deliver natively integrated cybersecurity, data protection and endpoint management. Powered by Perception Point, the service uses API-based cloud deployment with pre-delivery detection and scans 100% of email traffic in under 30 seconds. It supports Microsoft 365, Google Workspace and Open-Xchange mailboxes; protection for on-premises mailboxes requires MX record configuration.

It blocks spam, phishing, QR-code phishing (quishing), BEC, spoofing, malware, advanced persistent threats and zero-day attacks, and detects and mitigates account takeover (ATO). Detection combines AI-powered threat analysis, image recognition, recursive unpacking of files and URLs, machine-learning-based anti-spoofing with DMARC, DKIM and SPF record checks, URL reputation checks, and CPU-level dynamic analysis.

MSPs and MSSPs that already deliver, or want to deliver, backup and security as managed services to small and midsized clients. The integrated platform model is most valuable when an MSP wants one console, one agent and one billing relationship to cover backup, endpoint, email and management.

Consumption-based and per-workload pricing through the Acronis Partner Program. Specific rates are partner-tier dependent. Monthly billing is supported, and a free trial of Acronis Email Security is available.

If you are an MSP delivering, or planning to deliver, more than one of backup, endpoint, email or RMM as a managed service, Acronis Email Security is the strongest fit for MSPs pursuing platform consolidation. The combined value of one console, one agent and one billing relationship often provides operational advantages over managing multiple point solutions. Start with Acronis Cyber Protect Cloud and add the Email Security service.

Summary: Baseline email protection for organizations standardized on Microsoft 365. Useful as a starting point, often supplemented by a third-party platform.

Microsoft Defender for Office 365 is bundled into most Microsoft 365 enterprise plans and provides phishing defense, malware scanning, Safe Links, Safe Attachments and anti-phishing policies natively in Microsoft 365 tenants.

Microsoft-only environments where the client has limited budget and accepts the trade-off of a single-vendor security baseline. Often supplemented by a dedicated email security platform for clients with higher risk profiles.

Native integration with Microsoft 365 identity, audit logs and the rest of the Defender suite.

Bundled into most Microsoft 365 enterprise SKUs. Per-seat add-on pricing for higher tiers is available directly from Microsoft.

Treat Microsoft Defender for Office 365 as the floor, not the ceiling. For most MSP clients, layer a dedicated email security platform on top, especially for clients in finance, legal, healthcare or any vertical with elevated BEC risk.

Summary: Best for MSP clients with heavy compliance, archiving and email continuity requirements.

Mimecast is an established email security vendor with a SEG-rooted architecture and a more recent ICES offering layered behind Microsoft 365. The platform combines threat protection with email archiving, continuity and data governance.

Regulated clients (financial services, legal, public sector) that need long-term email retention, e-discovery and continuity in addition to threat protection.

Per-user, multi-tier subscription pricing. MSP rates depend on partner tier and client volume.

A reasonable choice for MSPs with regulated clients where archiving and continuity carry as much weight as inbox threat protection. For lighter-touch SMB portfolios, the price-to-value ratio is harder to justify.

Summary: Email-only platform built specifically for MSPs.

Mesh is positioned as an email security platform built exclusively for the MSP channel. It offers MX-based gateway, API-based mailbox protection and a unified deployment that combines both.

MSPs that want a focused email-only platform with billing, licensing and provisioning workflows designed around channel realities, especially MSPs that are not pursuing a full integrated platform play.

MSP-only commercial model, monthly billing supported. Pricing is partner-tier dependent.

Worth evaluating for MSPs whose strategy is best-of-breed point solutions rather than platform consolidation, especially MSPs migrating from legacy SEGs.

Summary: Best for MSPs that want highly visible end-user phishing warnings on every email.

INKY is a mailbox-level email security platform built for MSPs and MSSPs. Its hallmark is the colored banner appended to every email indicating risk level and the specific reasons an email was flagged.

MSPs whose clients have high end-user awareness needs and want visible, in-banner education on every message.

Per-user MSP pricing through the partner channel.

A solid pick for MSPs serving SMB clients where end-user phishing awareness is a primary risk driver and where the banner experience fits the client culture.

Summary: SMB-friendly email security with a strong Microsoft 365 partnership.

Vade is a partner-focused email security vendor with a particular emphasis on SMB segments and a longstanding Microsoft 365 partnership. The platform uses AI and behavioral analysis layered on top of Microsoft 365 native protections.

MSPs with SMB-heavy portfolios that need a price-competitive email security layer that complements Microsoft 365.

Per-user MSP pricing. Often the most economical of the dedicated platforms for small client environments.

A reasonable choice for MSPs with predominantly SMB portfolios where price-to-protection ratio is the primary consideration.

Email security platforms block the message before the user interacts with it. They do not, by themselves, address what happens after a credential is stolen, an account is compromised, or ransomware is already running on an endpoint. For MSPs delivering a complete service, several adjacent capabilities round out the protection envelope.

Endpoint detection and response (EDR). When a user clicks a malicious link that the email platform missed, the line of defence is the endpoint. EDR detects the malicious process, isolates the device, and gives an analyst the timeline to respond. Acronis pairs Acronis Email Security with Acronis EDR in the same console, reducing context switching during investigation and response.

Incident Response services. Managed Incident Response services are available for MSPs that want specialist support during complex incidents.

Backup and recovery for Microsoft 365 mailboxes. If a phishing attack leads to ransomware on a mailbox, or an account takeover that deletes data, the inbox itself needs a restore point. Email security blocks the attack; backup is the safety net when something gets through.

Security awareness training. The Verizon DBIR 2025 found that even with continuous training, the median phishing simulation click rate remains around 1.5%. Training does not eliminate clicks, but it dramatically improves reporting rates: trained employees report simulated phishing emails far more frequently, which gives the SOC the human sensor network needed to contain a campaign. Acronis Security Awareness Training is a separate Acronis Cyber Protect Cloud add-on that pairs with the Email Security service.

The point: a single email security platform, however good, is one layer. These adjacent capabilities help MSPs build a more complete protection model for clients.

The right answer depends on what you are optimizing for.

A useful sanity check before any final decision: run a free email threat assessment on a representative client tenant with the platform's own scanning tool, and ask the vendor for two reference MSPs with portfolios similar to yours.

A SEG sits in front of the mailbox in the mail flow path and inspects messages before delivery. ICES integrates with Microsoft 365 or Google Workspace via API and inspects email inside or alongside the cloud mailbox environment. Most modern platforms are ICES or ICES-plus-SEG hybrids. Acronis Email Security uses API-based cloud deployment with pre-delivery detection, combining fast onboarding for Microsoft 365 and Google Workspace with protection before messages reach users.

For most MSP clients, no. Defender for Office 365 is a strong baseline for Microsoft 365 environments but typically misses advanced phishing, BEC and zero-day attacks that dedicated platforms catch. Most mature MSPs layer a dedicated email security platform on top.

Email authentication standards help prevent domain spoofing and are essential. They are not, on their own, an email security platform. Acronis Email Security uses machine-learning-based anti-spoofing with DMARC, DKIM and SPF record checks as part of inbound inspection. For domain-level DMARC enforcement across many client domains, MSPs should evaluate dedicated DMARC platforms such as Sendmarc and EasyDMARC.

Modern API-based email security platforms, including Acronis Email Security, can deploy in minutes. There is no MX record change required for API integration with Microsoft 365 or Google Workspace. Protection for on-premises mailboxes requires MX record configuration. SEG-architecture platforms typically take longer because of MX record changes and policy migration.

Email security blocks the attack at the inbox. Backup and recovery is the safety net if something gets through, including ransomware that encrypts mailboxes. Acronis pairs email security with Backup for Microsoft 365 and Acronis EDR in a single platform, which means an MSP analyst sees email, endpoint and backup signals on the same console without context switching.

Increasingly, yes. Most cyber insurance underwriters now ask whether the insured has multi-factor authentication on email, advanced phishing protection beyond native M365 controls, and email backup separate from the production mailbox. MSPs delivering email security as part of a managed service should be able to evidence each control on a per-client basis. Platforms with native multitenant reporting make that audit trail easier to produce.

If your MSP is evaluating a new email security platform, the most efficient path is to (1) define which of the six criteria above matter most to your client portfolio, (2) trial two or three platforms on a representative client tenant, and (3) compare detection results, false positives and analyst experience side by side.

To explore what an integrated approach looks like, see Acronis Cyber Protect Cloud , the Acronis Email Security product page , or start a free trial .

For a deeper read on what email threat prevention looks like in practice, see What is email threat prevention? A complete guide 2026 .