Email security software filters inbound messages for phishing links, malicious attachments, spam and business email compromise (BEC) before they reach an inbox, deploying as an inline gateway or via API alongside Microsoft 365 or Google Workspace.
This guide ranks the platforms on what actually separates them once the demo is over: how the vendor's own ownership and jurisdiction line up with its marketing, whether deployment is cloud-only or genuinely flexible, and what a team actually gets for a quote-only price nobody publishes.
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In short
What email security software does
Email security software, also called a secure email gateway or anti-phishing platform, inspects inbound and sometimes outbound email for spam, malware, phishing links and business email compromise before a message reaches its recipient. Most products in this category deploy either as an inline gateway sitting between the internet and the mail server, or via API alongside Microsoft 365 or Google Workspace, and price per mailbox rather than per user.
In this order: setup effort, what it really costs, how your data comes back out, whether
you can leave, and who each email security tool is built for. One rule sits on top of those tests:
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. Why those five, and why there is no
score out of ten, is on the how we work page.
A wide bundle across three plans: threat protection, account takeover protection, DMARC reporting and encryption, with backup, archiving and training on the upper plans
Quoted on request; not published; free trial on request
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Irish, MSP-channel-established spam and malware gateway, with BEC detection sold separately as PhishTitan
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Country is where the vendor is headquartered or contracts from, which is a
different question from where your data is hosted. Where the two tell different stories, the
entry says so.
Cisco's cloud-scale gateway, deployable inline or via API, with FedRAMP High certification
Ranked #1 of 12 in Best Email Security Software in 2026.
Self-hostablePricing on requestNorth America
Cisco Secure Email covers a gateway sold with cloud, on-premises and hybrid licences, and Secure Email Threat Defense, which delivers 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. Cisco is headquartered in San Jose, California. The product's clearest advantage shows up inside an existing Cisco security stack, where identity, network and endpoint signals it already collects can feed the same threat picture; as a standalone point solution it competes on roughly the same terms as the other US gateways in this list.
What stands out
FedRAMP High certified
On-premises option
Pricing on request
North America
United StatesQuoted per user on 1, 3 or 5-year terms; no published pricing; free trial of Threat Defense
Italian, privacy-first email gateway with AI-layered filtering and a rare genuine on-premises option
Ranked #2 of 12 in Best Email Security Software in 2026.
Self-hostablePricing on requestEurope
Libraesva has protected business email since 2013 from its base in Lecco, Italy. In April 2026 Libraesva acquired Cyber Guru, another Italian cybersecurity firm, and launched LibraCyber, which it describes as "a new European cybersecurity leader"; the Italian parent is now LibraCyber S.p.A. The core product, Libraesva Email Security, uses AI-powered layered protection to stop threats before they reach an inbox, and the combined group now also offers email archiving, DMARC protection and phishing-simulation training alongside it.
Libraesva markets itself explicitly as "privacy-first" and serves regulated sectors including financial services, healthcare and government. It is one of the few vendors in this category still offering a genuine on-premises deployment option alongside private and public cloud, not cloud-only. It also runs regional entities in the UK (Libraesva Limited) and the US (Libraesva Inc), which is worth knowing even though the parent company and controlling entity remain Italian. Pricing is not published; a 30-day free trial is offered.
What stands out
On-premises option
Free trial
Europe
ItalyQuoted per mailbox on request; 30-day free trial offered
Independent, owner-managed German gateway with genuine cloud-or-on-premises choice and encryption built in
Ranked #3 of 12 in Best Email Security Software in 2026.
Self-hostablePricing on requestEurope
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. It carries the "IT Security made in Germany" certification and reports more than 6,000 customers.
What separates NoSpamProxy from most of this list is genuine deployment choice: NoSpamProxy Cloud or NoSpamProxy Server (on-premises), not a cloud-only product with an on-prem story bolted on. S/MIME and PGP email encryption with automated certificate management, large-file transfer direct from the email client, and GDPR-compliant disclaimer management are bundled in rather than sold as separate add-ons.
What stands out
On-premises option
Pricing on request
Europe
GermanyQuoted on request; not published; 30-day trial of Cloud or Server
The category's default enterprise choice, analyzing roughly 2.6 billion emails a day via gateway or API
Ranked #4 of 12 in Best Email Security Software in 2026.
Pricing on requestNorth America
Proofpoint is the name most enterprise security teams default to first in email security: Core Email Protection deploys as a gateway or via API and covers both Microsoft 365 and Google Workspace, with packages running from Core up to Prime, and the company says it inspects roughly 2.6 billion emails a day for threats and compliance risk.
It is a US company, founded in 2002 and headquartered in Sunnyvale, California. Proofpoint also now owns Hornetsecurity (see below), which means two products in this ranking answer to the same US parent. Pricing is quoted on user licences and contract term rather than published, and deals are typically sized for mid-market and enterprise mailbox counts rather than small teams.
What stands out
Pricing on request
North America
United StatesQuoted per organization by user licences and contract term; not published
Behavioral-AI platform built specifically for BEC and executive impersonation, deployed via API alongside your existing filter
Ranked #5 of 12 in Best Email Security Software in 2026.
Pricing on requestNorth America
Abnormal AI, formerly Abnormal Security, is a San Francisco company founded in 2018 and 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.
It connects via API to Microsoft 365 or Google Workspace rather than sitting inline as a traditional gateway, so it complements rather than replaces primary spam/malware filtering. The company says it is trusted by 5,000 organisations, including more than 30% of the Fortune 500, and has since added identity and AI-agent security products; it is configured to act autonomously on threats once given the access to do so. It is US-headquartered and prices strictly on request.
What stands out
API deployment
Pricing on request
North America
United StatesQuoted on request; no published pricing
Mature UK-founded suite mapping the attack chain across email, human behavior, endpoints and data
Ranked #6 of 12 in Best Email Security Software in 2026.
Pricing on requestEurope
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.
Continuity and archiving, Mimecast's original heritage, are still sold alongside it, and it deploys either as an inline gateway or via API with no MX record changes. Mimecast was taken private by Permira in 2022, so it no longer carries the public-market disclosure it once did. It remains UK-headquartered, which means UK law applies, not EU or EEA law, even though the company has long marketed itself around European compliance needs.
What stands out
Pricing on request
Europe
United KingdomQuoted on request; no published pricing
A wide bundle across three plans: threat protection, account takeover protection, DMARC reporting and encryption, with backup, archiving and training on the upper plans
Ranked #7 of 12 in Best Email Security Software in 2026.
Pricing on requestNorth America
Barracuda Networks, headquartered in Campbell, California and owned by KKR since 2022, sells Email Protection as three plans rather than a single point product. Advanced covers spam, malware and advanced threat protection, account takeover protection, DMARC reporting, email encryption, continuity and data loss prevention; Premium adds unlimited Microsoft 365 backup; Premium Plus adds cloud archiving and security awareness training.
It supports both Microsoft 365 and Google Workspace. Account takeover protection is included from the entry plan, which matters specifically for catching an already-compromised internal mailbox being used to attack others. Pricing is quoted on request and scaled by plan and mailbox count.
What stands out
Pricing on request
North America
United StatesQuoted on request; no published pricing
German-founded, MSP-channel-scale email security suite, now a Proofpoint subsidiary, not an independent European alternative
Ranked #8 of 12 in Best Email Security Software in 2026.
Pricing on requestEurope
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. In 2024, France-based Vade joined the Hornetsecurity Group, and Hornetsecurity had already absorbed France's Altospam (altospam.com now redirects straight to hornetsecurity.com).
The detail that matters most for a European buyer: Hornetsecurity is now a subsidiary of Proofpoint, a US company. The current site is branded "Hornetsecurity by Proofpoint," its CEO and COO hold titles inside "Proofpoint MSP Platform," and the legal footer links to "Proofpoint's Position on the U.S. CLOUD Act." Whatever its German engineering heritage, it does not currently offer EU-independent jurisdiction, which is why it is listed here as a global option rather than a European one.
What stands out
MSP channel
Pricing on request
Europe
GermanyQuoted on request across four 365 Total Protection plans; no published pricing; free trial offered
Privately owned Munich vendor marketed explicitly as email security 'made in Europe', gateway or API
Ranked #9 of 12 in Best Email Security Software in 2026.
Pricing on requestEurope
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 (Google Workspace is listed as planned), 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.
Retarus markets the product explicitly as "the comprehensive solution for email security made in Europe" and describes it as GDPR-compliant, saying all its AI components are operated within the EU. Email security is one line in a broader Retarus messaging portfolio that also includes cloud fax, SMS, transactional email and EDI, rather than the company's sole focus.
French SMB-focused filter, deployed by native API for Microsoft 365, with named anti-spearphishing detection and click-time link analysis
Ranked #10 of 12 in Best Email Security Software in 2026.
Pricing on requestEurope
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.
The company says it analyzes more than 6 billion emails a year and deploys as a native API for Microsoft 365, with no DNS changes and post-delivery remediation of messages already delivered. Naming spearphishing as its own detection layer, separate from generic phishing, signals a specific focus on targeted attacks against individuals rather than mass spam campaigns. Pricing is not published; the company directs prospects to request a demo rather than offering a self-service trial.
Vienna-built gateway with all development, processing and support kept in-house in Austria
Ranked #11 of 12 in Best Email Security Software in 2026.
Published pricingEurope
IKARUS Security Software 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. The product blocks spam, phishing, malware and dangerous URLs through content and behavior analysis, and re-checks links in real time both when a message is delivered and again at the moment a user clicks.
An optional Advanced Threat Protection add-on adds sandboxing through Trellix Intelligent Virtual Execution for suspicious files and zero-day exploits, and IKARUS offers S/MIME certificates through a partnership with Certum for encryption and digital signing. It is the smallest vendor by public footprint in this EU set, and pricing is quoted on request.
What stands out
Pricing on request
Europe
AustriaQuoted on request; not published; free test and a public demo interface
Irish, MSP-channel-established spam and malware gateway, with BEC detection sold separately as PhishTitan
Ranked #12 of 12 in Best Email Security Software in 2026.
Pricing on requestEurope
SpamTitan is built by TitanHQ, the trading name of Copperfasten Technologies Ltd, registered in the Republic of Ireland; TitanHQ has since merged with Redstor and now trades as part of CyberSentriq. It blocks spam, viruses, malware, ransomware and links to malicious websites using RBLs, recipient verification, SPF, DKIM and DMARC; the "multiple layers of analysis and detection methods" TitanHQ markets for business email compromise belong to PhishTitan, a separate API product for Microsoft 365.
It works natively alongside Microsoft 365. TitanHQ is long established in the managed-service-provider channel, also selling WebTitan (DNS filtering) and ArcTitan (email archiving), which makes SpamTitan an easy add for an MSP already reselling those. Pricing is not published; prospects choose or design a bundle and TitanHQ's sales team follows up.
What stands out
MSP channel
Pricing on request
Europe
IrelandQuoted on request; not published; free trial on request
Email security software, also called a secure email gateway or anti-phishing platform, inspects inbound and sometimes outbound email for spam, malware, phishing links and business email compromise before a message reaches its recipient. Most products in this category deploy either as an inline gateway sitting between the internet and the mail server, or via API alongside Microsoft 365 or Google Workspace, and price per mailbox rather than per user. The differences that matter are rarely in the feature list, so this is
the order we would work through them.
01
Decide whether you need a published price
1 of the 12 tools here publish what they cost; the other 11 quote per organisation. The ones you can compare without a sales call: IKARUS.
02
Decide how much the jurisdiction matters
These 12 vendors are established in 7 countries across 2 regions (Europe 8, North America 4). That decides whose disclosure law applies to what the vendor holds, wherever the servers are.
Gateway in front of the mailbox, or API beside it
An inline gateway receives mail before your server does, which means redirecting MX records and accepting a new dependency in the delivery path. An API product reads mailboxes inside Microsoft 365 or Google Workspace instead.
Abnormal AI is API-only and complements an existing filter; NoSpamProxy, Libraesva and IKARUS are gateways; Proofpoint, Mimecast, Cisco Secure Email and Retarus offer either route, and Mailinblack connects by API to Microsoft 365.
Ask what happens to inbound mail while the gateway itself is unavailable.
For API tools, check how long a malicious message can sit in an inbox before removal.
Confirm whether Google Workspace is supported or only Microsoft 365.
Impersonation with no link and no attachment is the hard case
Spam and known malware are largely solved; payment fraud written in plain text is not. Abnormal AI models normal behaviour per identity to spot a changed bank account or an unusual request.
Barracuda includes account takeover protection in every plan, and Proofpoint sells it within its packages, for the compromised internal mailbox. Mailinblack lists spearphishing as its own layer, while NoSpamProxy advertises CEO-fraud detection and TitanHQ sells BEC detection separately as PhishTitan.
Replay a real fraud attempt your organisation received and see which layer flags it.
Ask whether mail sent between internal mailboxes is inspected at all.
Check that links are examined again after delivery, as IKARUS, Mailinblack and Retarus describe.
The owner is not always who the brand suggests
Several names here have changed hands. Hornetsecurity, German-founded, is now a Proofpoint subsidiary, so two entries on this page share a US parent. Mimecast is London-based and owned by Permira; Barracuda belongs to KKR; TitanHQ, maker of SpamTitan, is now part of CyberSentriq.
NoSpamProxy and Retarus are independent and privately held, IKARUS keeps development and processing in Austria, and Libraesva's parent, LibraCyber, is Italian. Where jurisdiction is a requirement, verify the parent.
Ask which legal entity signs the contract and who its ultimate parent is.
Request the list of countries where message content is processed and stored.
If on-premises is mandatory, start with NoSpamProxy Server and Libraesva, then Cisco's on-premises gateway licences.
Bundle contents explain most of the gap between quotes
No vendor on this page publishes a price, and scope accounts for much of the spread. Barracuda puts encryption in every plan, adds backup on Premium and keeps archiving and training for Premium Plus; NoSpamProxy includes S/MIME and PGP encryption; IKARUS sells sandboxing as an optional extra.
Hornetsecurity and SpamTitan sell heavily through managed service providers, so a smaller firm may end up buying through its IT partner.
List what you already own for archiving, backup and awareness training before accepting a bundle.
Ask whether sandboxing and encryption are inside the base price per mailbox.
Check how shared and service mailboxes are counted.
What goes wrong most often when buying email security software
Adding an API tool such as Abnormal AI and switching off the filter it was designed to sit beside.
Choosing Hornetsecurity for independent European jurisdiction without noticing it now belongs to Proofpoint.
Testing only with spam and malware samples when the costly attacks are plain-text payment requests.
Paying for bundled archiving, backup or training that duplicates tools already in use.
07
Frequently asked questions
7 answers
What is the best email security software in 2026?
Cisco Secure Email leads our ranking of 12. Cisco Secure Email covers a gateway sold with cloud, on-premises and hybrid licences, and Secure Email Threat Defense, which delivers 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. Cisco is headquartered in San Jose, California. The product's clearest advantage shows up inside an existing Cisco security stack, where identity, network and endpoint signals it already collects can feed the same threat picture; as a standalone point solution it competes on roughly the same terms as the other US gateways in this list.
Which email security tools publish their pricing?
1 of the 12, with the pricing model each one publishes:
IKARUS: Quoted on request; not published; free test and a public demo interface.
The other 11 quote per organisation.
Is there a free email security tool?
No. None of the 12 offer a usable free tier.
Where are these email security software vendors established?
In 7 countries across 2 regions: Europe 8, North America 4.
Cisco Secure Email: United States.
Libraesva: Italy.
NoSpamProxy: Germany.
Proofpoint: United States.
Abnormal AI: United States.
Mimecast: United Kingdom.
Barracuda: United States.
Hornetsecurity: Germany.
Retarus: Germany.
Mailinblack: France.
IKARUS: Austria.
SpamTitan (CyberSentriq): Ireland.
Which email security tools can you host yourself?
Cisco Secure Email, Libraesva, NoSpamProxy. The other 9 are hosted by the vendor only.
What should you use instead of Cisco Secure Email?
Libraesva and NoSpamProxy are the next two on this page. Libraesva is for Italian, privacy-first email gateway with AI-layered filtering and a rare genuine on-premises option; NoSpamProxy is for Independent, owner-managed German gateway with genuine cloud-or-on-premises choice and encryption built in.
Who should not buy Cisco Secure Email?
Cisco Secure Email covers a gateway sold with cloud, on-premises and hybrid licences, and Secure Email Threat Defense, which delivers 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. Cisco is headquartered in San Jose, California. The product's clearest advantage shows up inside an existing Cisco security stack, where identity, network and endpoint signals it already collects can feed the same threat picture; as a standalone point solution it competes on roughly the same terms as the other US gateways in this list.
If your email security software product belongs among these 12, tell us what it does and who it is for. Inclusion is an editorial call; what a listing is and is not is set out under software advice.
