e-POST
e-POST (株式会社イー・ポスト) is a privately held Japanese software vendor, founded in 2003 and based in Tokyo, that develops and sells the E-Post series of Windows-native, on-premise mail server software — including mail, SMTP gateway, supervisor-approval, and inbound-security products — serving Japanese enterprises, government agencies, municipalities, hospitals, and educational institutions through direct sales and an 80+ SI partner channel.
- Company typePrivate
- Founded2003
- HeadquartersTokyo, Japan
- Headcount1–10
- GTM typeB2B
- OfferingSoftware
What e-POST does
e-POST Inc. (株式会社イー・ポスト) is a privately held Japanese software vendor founded in 2003 and headquartered in Takadanobaba, Shinjuku, Tokyo, under Representative Director Kazuya Imanishi (今西 和也). The company develops and sells the E-Post series of Windows-native, on-premise mail server software, marketed as "fully domestic Japanese development" with no foreign product or open-source code dependency and all documentation in original Japanese. Its core portfolio consists of four products: E-Post Mail Server (x64) — a full-featured mail server supporting SMTP, POP3, and IMAP4 with HA clustering and Active Directory integration; E-Post SMTP Server (x64) — a standalone SMTP gateway with delivery speeds up to approximately 300,000 emails per hour; E-Post BossCheck Server (x64) — a supervisor-approval add-on for outbound email to prevent misdirected and sensitive communications; and E-Post Secure Handler (x64) — an inbound mail screening gateway with 23-point heuristic inspection and admin-approval workflows for targeted-attack defense. Supporting sub-brands include the E-Post V-Series secure mail appliance, E-Post Mobile Mailer for emergency notification, the LGWAN Option for Japanese local-government networks, and the AUTOUSER CGI tool for Delta Chat account provisioning.
The underlying technology is a 64-bit native (x64) Windows server stack supporting Windows Server 2016/2019/2022/2025, compatible with Hyper-V, VMware, and IaaS environments (AWS, Oracle Cloud Infrastructure). Architecture features dual SMTP services (EPSTRS for receive, EPSTDS for delivery), active-standby HA clustering via IP Watcher, and a DMARC/DKIM/SPF authentication add-on (EPSTDMARC). E-POST makes money through one-time perpetual software licenses sold per seat in 50/100/250 user tiers, recurring annual support and database-update subscriptions (including the spam-link database for Secure Handler), and professional services for migration, HA cluster deployment, and Active Directory integration.
Go-to-market combines direct online sales via the E-POST Direct website, a 30-day free evaluation download for product-led evaluation, and an extensive channel of approximately 80+ Japanese SI vendors and system integrators — including NTT Data, Fujitsu, NEC, SCSK, TIS, Hitachi group entities, and Otsuka Shokai — that recommend and deploy E-Post products into enterprise, government, and public-sector accounts. The company serves customers across manufacturing, finance, healthcare, broadcasting, wagering, construction, real estate, and a large base of universities and K-12 educational institutions, with cumulative deployment of thousands of servers across Japan. Marketing relies on the corporate website, technical construction guides, PR TIMES press releases, and participation in Japan IT Week and 自治体・公共Week exhibitions.
e-POST firmographics
Firmographics- Name
- e-POST
- Legal name
- 株式会社イー・ポスト
- Website
- https://e-postinc.jp
- Company type
- Private
- Founded year
- 2003
- Operating status
- Operating
- Headcount range
- 1–10 employees
- Short description
- e-POST (株式会社イー・ポスト) is a privately held Japanese software vendor, founded in 2003 and based in Tokyo, that develops and sells the E-Post series of Windows-native, on-premise mail server software — including mail, SMTP gateway, supervisor-approval, and inbound-security products — serving Japanese enterprises, government agencies, municipalities, hospitals, and educational institutions through direct sales and an 80+ SI partner channel.
- Ownership category
- akta.pro rank
Where e-POST is headquartered
LocationHeadquarters
- HQ city
- Tokyo
- HQ country
- Japan
- HQ region
- Asia
Offices1 record
Markets served
e-POST business model
Business model- GTM type
- B2B
- Offering type
- Software
- Cost components
- Personnel, Technology or R&D, Marketing or Sales, Operations
Revenue model
- Software License Sales: One-time perpetual license sales for E-Post Mail Server, E-Post SMTP Server, E-Post Secure Handler, and E-Post BossCheck Server products. User-based licensing (50/100/250 user tiers). Both single server and cluster model versions available.
- Annual Support and Update Subscriptions: Annual subscription renewal for license key updates, virus pattern database downloads, spam link database updates, and ongoing technical support. Required for continued database update functionality.
- System Construction Services: Implementation and system construction services including data migration from existing mail servers, system setup, HA cluster configuration, and Active Directory integration. Includes services for large-scale broadcast mailing systems and emergency notification systems.
Pricing tiers
| Model | Billing | Price |
|---|---|---|
| Per seat | Annual | E-Post Secure Handler (x64) - 50 User Single Server |
| Per seat | Annual | E-Post Secure Handler (x64) - 100 User Single Server |
| Per seat | Annual | E-Post Secure Handler (x64) - 250 User Single Server |
Go-to-market motion1 record
Distribution channels4 records
Marketing channels5 records
e-POST product offering
Product offeringCore offering
e-POST is a Japanese mail server software development vendor that builds and sells Windows-native on-premise mail server products. The company develops, sells, and supports the E-Post series, including the E-Post Mail Server, E-Post SMTP Server, E-Post BossCheck Server, and E-Post Secure Handler, along with related solutions and implementation services. All software is purely domestically developed in Japan with no dependency on overseas products or open source code.
Product overview
e-POST is a mail server software developer offering a suite of Windows-native on-premises mail server products. The core portfolio consists of four main software products: E-Post Mail Server (x64) — a full-featured mail server with SMTP/POP3/IMAP4; E-Post SMTP Server (x64) — a standalone SMTP gateway for relay, spam filtering, and sender authentication; E-Post BossCheck Server (x64) — a manager-approval add-on for preventing misdirected and sensitive outbound mail; and E-Post Secure Handler (x64) — an inbound mail screening gateway using 23-point heuristic analysis and admin approval workflows to defend against targeted attacks and phishing. The portfolio is sold as individual on-premises software licenses with optional professional implementation services. E-Post Mail Server and E-Post SMTP Server are available in Standard and Enterprise/Enterprise II tiers, while BossCheck Server and Secure Handler are add-on modules. All products are 64-bit (x64) native for Windows Server 2016/2019/2022/2025.
Differentiator
Problem solved
Functional benefit
Brands
- E-Post Mail Server: Windows-compatible mail server software supporting SMTP, POP3, IMAP4 protocols with features including HA cluster configuration, SSL/TLS encryption, and Active Directory integration.
- E-Post SMTP Server
- E-Post Secure Handler
- E-Post BossCheck Server
- E-Post Vシリーズ
- E-Post Mobile Mailer
- E-Post LGWAN Option
Products and services
- E-Post Mail Server (x64) 64-bit Windows-native mail server software providing SMTP, POP3, IMAP4, anti-spam, anti-virus (Enterprise II tier), HA clustering, Active Directory integration, and web management. Supports up to tens of thousands of mailboxes. Available in Standard, Enterprise, and Enterprise II feature tiers.
- E-Post SMTP Server (x64) Standalone 64-bit SMTP gateway software for Windows, handling mail relay, spam filtering, relay restrictions, and DMARC/DKIM/SPF authentication. Delivers up to approximately 300,000 emails per hour. Available as a standalone gateway or embedded within E-Post Mail Server. Supports up to 512 managed domains.
- E-Post BossCheck Server (x64) Manager-approval mail security software that holds outgoing emails for supervisor review before delivery, preventing misdirected communications and information leaks. Targets enterprises, government agencies, and healthcare organizations.
- E-Post Secure Handler (x64) Inbound mail approval and auto-judgment mail gateway software for targeted attack and phishing defense. Screens inbound mail against 23 heuristic checks, holds suspicious mail for admin approval, and auto-learns to populate whitelist and blacklist. Available in 50, 100, and 250 user tiers with bundled E-Post SMTP Server or embedded in E-Post Mail Server.
- E-Post V Series Secure mail server appliance series built around E-Post mail server software for organizations seeking pre-configured hardware-based deployments.
- E-Post Mobile Mailer
Quantifiable outcome
- Thousands of servers deployed domestically across enterprises, government agencies, municipalities, and educational institutions
- +2 more outcomes
Companies that use e-POST
Customer profileNamed customers8 records
Segments4 records
Ideal customer profiles4 records
e-POST technology and API
TechnologyTechnology focussed Yes
API detail
- Has API
- No
- API docs
- API detail
Core technology
AI maturity
App detail
Integration6 records
Feature5 records
e-POST partnerships and signals
Strategic signalPartnerships
Seven partnerships are on record, tiered core.
- NTT東日本株式会社 / NTT西日本株式会社coreMajor telecommunications carriers and SI vendors providing E-Post mail server solutions to their business customers.
- 株式会社NTTデータcoreLeading Japanese system integrator and global IT services company. Offers E-Post mail server solutions as part of comprehensive system integration services.
- NECネクサソリューションズ株式会社 / 日本電気株式会社coreMajor Japanese electronics and IT solutions company group recommending E-Post products for Windows-based mail server needs.
- 富士通株式会社 / 富士通Japan株式会社coreLeading Japanese IT infrastructure provider offering E-Post mail server as part of their Windows server solutions portfolio.
- SCSK株式会社 / TIS株式会社coreMajor Japanese system integrators with significant enterprise customer bases who recommend E-Post products.
- 株式会社日立システムズ / 株式会社日立ソリューションズ西山coreHitachi group system integrators offering E-Post mail server solutions to government and enterprise customers.
- 株式会社大塚商会coreMajor Japanese IT product distributor and SI vendor with extensive channel reach to small and medium businesses.
Scale indicators2 records
Recent moves6 records
Expansion highlights5 records
e-POST competitors and assessment
Company assessmentRegional players
- Internet Initiative Japan (IIJ): Major Japanese internet infrastructure provider offering hosted mail, messaging, and security services in Japan; comparable in geographic market but more focused on managed/cloud delivery rather than licensed on-premise Windows software.
- Sakura Internet: Japanese hosting provider offering mail and email services aimed at SMBs and developers; serves a similar Japanese customer base to E-POST but via hosted mail rather than licensed on-premise software.
Direct peers
- IceWarp: Cross-platform mail server software offering SMTP/IMAP/POP with built-in anti-spam, security gateway, and collaboration features; comparable product suite to E-POST's mail server offerings for mid-market Windows deployments and SMB on-premise mail.
- HCL Domino (formerly IBM Notes/Domino): Legacy enterprise mail server and collaboration platform; competes with E-POST in the on-premise mail server segment, particularly for organizations with established IBM heritage in Japanese government and large enterprise.
- Zimbra (Synacor): Open-source-derived mail and collaboration server offering on-premise email with security, calendaring, and document features; competes with E-POST for enterprise on-premise mail deployments, though primarily Linux-based rather than Windows-only.
- Microsoft Exchange Server: Microsoft's on-premise Windows-native mail server is the closest direct competitor to E-POST Mail Server in the Japanese market, with overlapping customer base and similar feature set including SMTP/IMAP/POP, Active Directory integration, HA clustering, and shared Windows Server support.
- Axigen: Mail server software providing SMTP/IMAP/POP with anti-spam, antivirus, and security features available on both Windows and Linux; comparable to E-POST for SMB and mid-market on-premise mail server deployments at similar price points.
Broad incumbents
- Proofpoint (Sendmail): Enterprise messaging security platform with mail infrastructure heritage through its Sendmail acquisition; overlapping target customers in regulated Japanese industries, particularly for inbound email security competing with E-Post Secure Handler.
- Google Workspace: Cloud-based mail (Gmail) and productivity suite; major competitor pulling Japanese enterprises — especially commercial SMB and tech-forward accounts — away from on-premise mail server solutions like E-POST.
- Microsoft 365 / Exchange Online: Cloud-based mail and productivity suite from Microsoft including Exchange Online; dominant alternative to on-premise Windows mail servers in Japanese enterprises and a primary substitute threat to E-POST's addressable market.
Market position
Strengths5 records
Weaknesses5 records
Competitive moat4 records
Key risks6 records
Key highlights7 records
Customer concentration
e-POST social profiles
Digital presencee-POST financial estimates
Financial estimateRevenue estimate
Valuation estimate
e-POST leadership team
Management profileNumber of profiles
Profiles1 record
e-POST funding detail
Funding detailFunding overview
Funding rounds
Investors
Funding detail is available on the Subscription and Enterprise plan.Contact sales →
e-POST M&A and investment
M&A and investmentM&A
Investments
M&A and investment is available on the Subscription and Enterprise plan.Contact sales →
Frequently asked questions about e-POST
What does e-POST do?
e-POST is a Japanese mail server software development vendor that builds and sells Windows-native on-premise mail server products. The company develops, sells, and supports the E-Post series, including the E-Post Mail Server, E-Post SMTP Server, E-Post BossCheck Server, and E-Post Secure Handler, along with related solutions and implementation services. All software is purely domestically developed in Japan with no dependency on overseas products or open source code.
Is e-POST a public or private company?
e-POST is a private company. It is classified as founder individual operated bootstrapped and is currently operating.
When was e-POST founded?
e-POST was founded in 2003. It employs 1 to 10 people.
Where is e-POST based?
e-POST is headquartered in Tokyo, Japan, in the Asia region.
How does e-POST make money?
Three revenue lines are on record. Software License Sales are the primary driver. The others are annual Support and Update Subscriptions and system Construction Services.
Who are e-POST's main competitors?
Regional players on record are Internet Initiative Japan (IIJ) and Sakura Internet. Direct peers are IceWarp, HCL Domino (formerly IBM Notes/Domino), Zimbra (Synacor), Microsoft Exchange Server and Axigen. Broad incumbents are Proofpoint (Sendmail), Google Workspace and Microsoft 365 / Exchange Online.
Does e-POST have an API?
No public API is recorded for e-POST.