Visibility in this ranking can be paid for. Payment moves a vendor's position within the
shortlist; it never adds a vendor, and it never changes a word of the review. The largest vendors in email security software
cannot hold places 1 to 3. Places 1 to 3 go to challengers, vendors outside the best-known brands in a category,
wherever the category has them; the established names follow from place 4 in their ranked order. How it works: placement disclosure ·
editorial process.
The 12 tools, reviewed
#1 Cisco Secure Email
Cisco's cloud-scale gateway, deployable inline or via API, with FedRAMP High certification · United States · cisco.com
FedRAMP Class D (High) Gateway or API deployment SE Labs AAA rated
Cisco Secure Email Threat Defense is Cisco's email security product, delivering what Cisco describes as cloud-scale, AI-driven gateway capabilities that inspect messages before delivery, using relationship graphs and contextual analysis to judge intent rather than scoring content alone. It deploys as an inline gateway or via API, and holds FedRAMP Class D (High) certification alongside an SE Labs AAA rating.
- Pricing: Quote only. Per-user subscription on 1-, 3- or 5-year terms, quoted on request; free trial for Microsoft 365. Free plan: free trial.
- Best for: FedRAMP Class D (High) certification and deep integration with an existing Cisco network and endpoint security stack.
- Strengths: Pre-delivery threat detection; Relationship-graph intent analysis; Inline gateway or API deployment.
Where it falls short
Best value is realized inside an existing Cisco security stack rather than as a standalone product, where it competes on roughly the same terms as the other gateways here.
Wrong for
A buyer with no other Cisco security products, who will not see the cross-product signal advantage that justifies the price for existing Cisco shops.
Visit Cisco Secure Email →
#2 Libraesva (LibraCyber)
Italian, privacy-first email gateway with AI-layered filtering and a rare genuine on-premises option · Italy · libraesva.com
Genuine on-premises option Privacy-first positioning 30-day free trial
Libraesva has protected business email since 2013 from its base in Lecco, Italy.
- Pricing: Free trial + quote only. Quoted per mailbox on request; 30-day free trial offered. Free plan: free trial.
- Best for: A genuine on-premises deployment option most cloud-native competitors no longer offer, from a privacy-first Italian vendor.
- Strengths: AI-powered layered threat protection; On-premises or private cloud deployment; Email archiving.
Where it falls short
Pricing is not published; requires a request quoting mailbox count.
Wrong for
A buyer who wants published, self-service pricing without a sales conversation.
Visit Libraesva (LibraCyber) →
#3 NoSpamProxy
Independent, owner-managed German gateway with genuine cloud-or-on-premises choice and encryption built in · Germany · nospamproxy.com
Cloud or on-premises Independent, owner-managed S/MIME & PGP built in
NoSpamProxy is built and sold by Net at Work GmbH, an independent, owner-managed company based in Paderborn, Germany, that says it operates with no external investors. The gateway sits between the mail server and the internet, filtering spam, malware and ransomware while also detecting phishing and CEO-fraud attempts.
- Pricing: Quote only. Quoted on request; 30-day free trial of Cloud or Server. Free plan: free trial.
- Best for: A genuine choice between cloud and on-premises deployment, with S/MIME/PGP encryption bundled in rather than sold separately.
- Strengths: Anti-spam/anti-malware/anti-phishing gateway; CEO-fraud (BEC) detection; S/MIME and PGP encryption, automated certs.
Where it falls short
Pricing is quote-only. Brand recognition is concentrated in the DACH region rather than internationally.
Wrong for
A buyer who specifically wants a cloud-only product with nothing to patch or maintain.
Visit NoSpamProxy →
#4 Barracuda
Tiered email protection from threat filtering up to backup, archiving and training · United States · barracuda.com
Widest feature bundle Account takeover protection KKR-owned since 2022
Barracuda Networks, headquartered in Campbell, California and owned by KKR since 2022, sells Email Protection in three tiers rather than as a single point product. Advanced covers spam, malware and advanced threat protection, account takeover protection, DMARC reporting, email encryption and data loss prevention; Premium adds Microsoft 365 backup; Premium Plus adds cloud archiving and security awareness training.
- Pricing: Quote only. Quoted on request across three tiers (Advanced, Premium, Premium Plus); free trial offered. Free plan: free trial.
- Best for: Account takeover protection as a named, distinct capability, catching an already-compromised mailbox before it is used to attack others.
- Strengths: Spam/malware/advanced threat protection; Account takeover protection; DMARC-based domain fraud protection.
Where it falls short
Owned by private equity firm KKR since 2022, so roadmap and renewal pricing answer to a private-equity timeline.
Wrong for
A buyer who only wants inbound threat filtering and already has separate backup, archiving and training tools in place.
Visit Barracuda →
#5 Hornetsecurity
German-founded, MSP-channel-scale email security suite, now a Proofpoint subsidiary rather than an independent vendor · Germany · hornetsecurity.com
125,000+ customers 12,000+ channel partners Now a Proofpoint subsidiary
Hornetsecurity was founded in Germany in 2007 by Daniel Hofmann and built a large MSP-channel business: the company says it serves over 125,000 customers in 120+ countries through more than 12,000 channel partners. Its 365 Total Protection suite bundles spam, phishing, malware, ransomware and advanced-threat filtering with email archiving, business continuity, compliance and security-awareness features for Microsoft 365.
- Pricing: Quote only. Quoted on request across four 365 Total Protection plans; free trial offered. Free plan: free trial.
- Best for: 125,000+ customers served through a 12,000-plus-partner MSP channel, with security, continuity, compliance and training bundled into one Microsoft 365 suite.
- Strengths: Spam/phishing/malware/ransomware filtering; Email archiving; Business continuity for Microsoft 365.
Where it falls short
Now a Proofpoint subsidiary: the site itself is branded "Hornetsecurity by Proofpoint" and links to Proofpoint's CLOUD Act position, so ownership, jurisdiction and roadmap sit with the same US parent as another product in this ranking.
Wrong for
A buyer seeking an independently owned alternative to Proofpoint: despite the German roots and brand, the current parent company is Proofpoint itself.
Visit Hornetsecurity →
#6 Retarus
Privately owned Munich vendor with a gateway or API option and post-delivery re-checking of links and attachments · Germany · retarus.com
Post-delivery re-checking Gateway or M365 API “Made in Europe”, 100% GDPR
Retarus is a privately owned, independent company headquartered in Munich, Germany, that describes itself directly: "we answer to customers not investors." Its Email Security product is offered as a classic secure email gateway or as an API for Microsoft 365, and it includes advanced threat protection with sandboxing, post-delivery protection that keeps re-checking links and attachments after arrival, and email continuity for outages.
- Pricing: Quote only. Quoted on request; not published. Free plan: none.
- Best for: Post-delivery protection that keeps re-checking links and attachments after arrival, on infrastructure marketed as 100% GDPR compliant.
- Strengths: Secure email gateway or Microsoft 365 API; Advanced threat protection with sandboxing; Post-delivery re-checking of links/attachments.
Where it falls short
Pricing is quote-only. Email security is one product line within a broader messaging portfolio (fax, SMS) rather than the company's sole focus.
Wrong for
A buyer who wants a single-purpose email security specialist rather than one line inside a broader messaging portfolio.
Visit Retarus →
#7 Mailinblack
French SMB-focused gateway with named anti-spearphishing detection and click-time link analysis · France · mailinblack.com
Click-time link analysis Named anti-spearphishing layer 6bn+ emails/year analyzed
Mailinblack is a French cybersecurity publisher based in Marseille with more than 20 years of experience. Its Protect product filters inbound email across six named threat types: anti-phishing, anti-spam, anti-malware, anti-spearphishing, anti-ransomware and link analysis that examines URLs at the moment they are clicked, not only at delivery.
- Pricing: Quote only. Demo required; no published pricing. Free plan: none.
- Best for: Click-time link analysis and a named anti-spearphishing layer, aimed specifically at targeted attacks rather than mass spam.
- Strengths: Anti-phishing and anti-spearphishing; Anti-spam and anti-malware; Anti-ransomware.
Where it falls short
Pricing is entirely demo-gated with no published trial terms. Smaller processing scale (6 billion emails a year) than the largest global gateways processing similar volumes daily.
Wrong for
A buyer who wants to see a price or start a trial before talking to sales.
Visit Mailinblack →
#8 SpamTitan (TitanHQ)
Irish, MSP-channel-established gateway with layered BEC detection, sold under the TitanHQ brand · Ireland · titanhq.com
MSP-channel established Layered BEC detection Companion products: WebTitan, ArcTitan
SpamTitan is built by TitanHQ, the trading name of Copperfasten Technologies Ltd, registered in the Republic of Ireland. It blocks spam, viruses, malware, ransomware and links to malicious websites, and the company markets "multiple layers of analysis and detection methods" specifically for business email compromise.
- Pricing: Quote only. Quoted on request; free trial offered. Free plan: free trial.
- Best for: Deep MSP-channel presence, with DNS filtering (WebTitan) and email archiving (ArcTitan) available as companion products from the same vendor.
- Strengths: Spam/virus/malware/ransomware blocking; Multi-layer BEC detection; Native Microsoft 365 integration.
Where it falls short
Pricing is quote-only via a "Get a Quote" form, no published rates. MSP/channel orientation means the direct-to-enterprise self-service buying experience is thinner than some rivals.
Wrong for
A large enterprise wanting a single global vendor already embedded across every regional office, rather than an MSP-friendly specialist.
Visit SpamTitan (TitanHQ) →
#9 IKARUS
Vienna-built gateway with all development, processing and support kept in-house in Austria · Austria · ikarussecurity.com
All-Austrian processing Real-time URL re-check at click Optional ATP sandboxing add-on
IKARUS Security GmbH is headquartered in Vienna, Austria, and states that all software development, data processing and support for mail.security are conducted in-house in Austria, with no subsidiary network to track.
- Pricing: Quote only. Quoted on request; free trial arranged through sales. Free plan: free trial.
- Best for: Every part of the service, development, data processing and support, kept in-house in Austria, with real-time URL re-checking at click time as well as delivery.
- Strengths: Anti-spam and antivirus filtering; Real-time URL defense at delivery and click; Optional ATP sandboxing (Trellix).
Where it falls short
One of the smallest public footprints of any vendor in this ranking, which matters for buyers doing vendor-risk reviews.
Wrong for
A buyer who wants zero-day sandboxing included in the base product rather than as an add-on.
Visit IKARUS →
#10 Proofpoint
The category's default enterprise choice, analyzing roughly 2.6 billion emails a day via gateway or API · United States · proofpoint.com
Roughly 2.6bn emails inspected/day Gateway or API deployment Owns Hornetsecurity
Proofpoint is the name most enterprise security teams default to first in email security: Core Email Protection deploys as an inline gateway or via API, with Collaboration Security Tier 2, Tier 3 and Prime packages layering on account takeover protection, awareness training and impersonation protection, and the company says it inspects roughly 2.6 billion emails a day for threats and compliance risk.
- Pricing: Quote only. Quoted per organization based on mailbox count; not published. Free plan: none.
- Best for: Threat-intelligence scale: roughly 2.6 billion emails inspected a day across the Proofpoint network, feeding detection for every deployment.
- Strengths: Inline gateway or API deployment; Threat intelligence from ~2.6bn emails/day; Compliance and DLP add-ons.
Where it falls short
As a US company it is subject to US legal process such as the CLOUD Act regardless of hosting location, which a buyer's counsel may want to review.
Wrong for
A small team wanting a self-service signup and a published price rather than a sales conversation.
Visit Proofpoint →
#11 Abnormal AI
Behavioral-AI platform built specifically for BEC and executive impersonation, deployed via API alongside your existing filter · United States · abnormal.ai
Behavioral AI for BEC API deployment, not inline 30%+ of Fortune 500
Abnormal Security, which now operates as Abnormal AI, is a San Francisco company, founded in 2018, built around a single idea: model normal behavior for every identity in an organization well enough that a deviation, a vendor invoice from a new bank account, an executive suddenly asking for a wire transfer, stands out on its own.
- Pricing: Quote only. Quoted on request; no published pricing. Free plan: none.
- Best for: Behavioral AI built specifically for BEC and impersonation, layered on top of an existing mailbox filter via API rather than replacing it.
- Strengths: Behavioral AI risk modeling per identity; BEC and executive-impersonation detection; Account takeover detection.
Where it falls short
Its API-only model means it is not a substitute for a primary inline gateway that also handles malware and attachment scanning at the perimeter, so most buyers run it next to another product.
Wrong for
An organization that needs a single product to handle both perimeter malware/attachment scanning and BEC detection, rather than two products working together.
Visit Abnormal AI →
#12 Mimecast
Mature UK-founded suite mapping the attack chain across email, human behavior, endpoints and data · United Kingdom · mimecast.com
Attack-chain correlation Continuity + archiving heritage Taken private by Permira, 2022
Mimecast is a London-headquartered company founded in 2003, and Advanced Email Security is its core threat-detection product: AI-powered analysis that the company says maps the full attack chain across email, human behavior, endpoints, AI agents and data rather than scoring messages in isolation. It deploys either as an MX-based inline gateway or via API with no MX change.
- Pricing: Quote only. Quoted on request; no published pricing. Free plan: none.
- Best for: Attack-chain correlation across email, endpoints, human behavior and data, built on two decades of continuity and archiving heritage.
- Strengths: AI-powered threat detection; Email continuity during outages; Cloud archiving.
Where it falls short
UK-headquartered, so the parent company sits outside the EU and EEA, which matters only to a buyer whose rules require EU or EEA incorporation.
Wrong for
A buyer whose compliance mandate specifically requires EU or EEA incorporation rather than UK.
Visit Mimecast →
Questions and answers
What is the best email security software in 2026?
Cisco Secure Email ranks first of 12, best for fedRAMP Class D (High) certification and deep integration with an existing Cisco network and endpoint security stack. Libraesva (LibraCyber) is second (a genuine on-premises deployment option most cloud-native competitors no longer offer, from a privacy-first Italian vendor) and NoSpamProxy third (a genuine choice between cloud and on-premises deployment, with S/MIME/PGP encryption bundled in rather than sold separately). Places 1 to 3 go to challengers, vendors outside the best-known brands, wherever the category has them.
Is Hornetsecurity a German or a US company?
Both, in a way that matters to a buyer.
Which of these vendors are independently owned, with no external parent?
Four: Libraesva (Italy, parent LibraCyber S.p.A.), NoSpamProxy (Germany, owned by independent, owner-managed Net at Work GmbH), Mailinblack (France) and IKARUS mail.security (Austria). Retarus (Germany) is also privately owned and independent.
Which of these tools offer on-premises deployment?
Libraesva, NoSpamProxy and SpamTitan all offer an on-premises option alongside cloud, unusual in a category that has moved almost entirely to cloud-only or SaaS delivery.
Is there a free email security tool?
Not a permanent free tier anywhere in this category.
What is the difference between a gateway and an API-based email security product?
A gateway (Proofpoint, Mimecast, Cisco, and most of the smaller vendors here) sits between the internet and the mail server and can block a message before it is ever delivered, usually by changing the domain's MX record to route mail through it first. An API-based product (Abnormal Security, Barracuda by default, and as an option Proofpoint, Mimecast, Cisco and Retarus) connects to Microsoft 365 or Google Workspace after the platform's own filtering has already run, adding detection, particularly for behavioral BEC signals, without changing mail flow.
How much does email security software cost?
None of the twelve vendors ranked here publish pricing. Enterprise email security is licensed per mailbox and quoted per organization, with the number appearing only after a sales conversation that typically starts with total mailbox count.
Which vendors here were acquired or taken private recently?
Four of the twelve changed hands in the last several years in ways that affect who ultimately controls the product: Proofpoint was taken private by Thoma Bravo in 2021, Barracuda Networks has been owned by KKR since 2022, Mimecast was taken private by Permira in 2022, and Hornetsecurity became a Proofpoint subsidiary, absorbing France's Vade in 2024 and having already folded in France's Altospam.
Do you get paid for these rankings?
Visibility in this ranking can be paid for. Payment moves a vendor's position within the shortlist; it never adds a vendor, and it never changes a word of the review.
How often is this ranking updated?
Whenever a fact underneath it changes: an acquisition like Hornetsecurity's move under Proofpoint, a pricing model shift, or a product that stops being maintained.
