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.
To rank email security tools we asked, in turn, how much work setup takes, what it truly costs, whether data can be taken back out, whether leaving is possible, and who the product suits. Challengers hold places 1 to 3 wherever the category has them. Established brands begin at place 4. Reasons for the choice of tests, and for skipping a score out of ten, can be read 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
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
The Proofpoint page lists immutable retention, legal holds, WORM-compliant preservation, self-service export and public REST APIs. Its FAQ names TLS 1.3 in transit, AES-256 at rest, SEC 17a-4 support and SOC 2 Type II.
The page says nothing on migration, so buyers moving from another archive should ask how much of that effort Proofpoint itself takes on, and at what price.
What stands out
Pricing on request
North America
Where it costs you
Supervision, Discover and Automate are add-ons, so the real price exceeds the base archive.
Only a demo is offered; no trial appears on the page.
Right for
Large regulated firms wanting supervision and discovery on top of the archive
Wrong for
Small teams that only need a mailbox archive
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 Cloud Archive lists retention policies, legal hold, advanced search and Archive for MS Teams. The legal entity shown is Mimecast Services Limited, with no head office stated on that page.
Because export is framed around search results, ask the vendor in writing how a full archive leaves before signing, especially if the archive will outlive any security contract you hold.
What stands out
Pricing on request
Europe
Where it costs you
The page describes export as a search and review capability, not a full exit.
No trial or published price appears; only a quote button.
Right for
Mimecast security customers who also want Teams and email archived
Wrong for
Buyers who want to verify a complete data exit first
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 gives auditors time-limited read access to a domain's archive, and administrators can review the audit log afterwards. Retention periods are adjustable, but the page names no figures.
Deleted mail returns with one button press, and PST or Outlook files can be imported from other databases. A fixed-price vendor export means the exit cost is known in advance, though the figure itself is not shown anywhere on the page.
What stands out
MSP channel
Pricing on request
Europe
Where it costs you
The page does not use the term eDiscovery, so legal-review depth is unproven.
No retention durations, storage region or price appear on the page.
Right for
Microsoft 365 firms already buying Hornetsecurity filtering, encryption or backup
Wrong for
Legal teams needing case management and review workflows
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
The Retarus archive page lists rule-based archiving, email search and import and export. Incoming encrypted mail is decrypted centrally before archiving through a master key, which keeps messages searchable.
The stated ten-year ceiling can limit regimes that demand longer retention. Archived mail can also be exported to external storage media, a point worth testing in a demo before you sign anything.
What stands out
API deployment
Pricing on request
Europe
Where it costs you
The archive page names no journaling method and no Microsoft 365 connector.
No price or trial appears; the page only offers an appointment.
Right for
European mid-size firms wanting ten-year mail retention at one vendor
Wrong for
Buyers who need to compare list prices before contact
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. Compare on the following points, in this order, before you compare features.
01
Decide whether you need a published price
The split is 1 published against 11 quoted. If you want to compare numbers first, start with IKARUS.
02
Decide how much the jurisdiction matters
Jurisdiction is a buying criterion here. The 12 vendors are spread over 7 countries (Europe 8, North America 4), and the home country determines which disclosure rules bind them.
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?
Not among the products reviewed here: no vendor on this list has a free tier worth using.
Where are these email security software vendors established?
Vendor countries on this page, Europe 8, North America 4:
What should you use instead of Cisco Secure Email?
Second is Libraesva, which suits Italian, privacy-first email gateway with AI-layered filtering and a rare genuine on-premises option. Third is NoSpamProxy, which suits 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.
