Every big company keeps the same quiet secret. Files leave the building all day long - a spec sent to a supplier, a clinical dataset shared with a partner, a term sheet emailed to a bank - and once they leave, almost nobody can say where they went. The usual fixes track the copy after it escapes. eSHARE, a software company in Waltham, Massachusetts, took the opposite view. The problem was never the tracking. The problem was the copy. So it built a product where the copy never happens.
The pitch fits on a sticker: share the link, not the file. When a customer uses eSHARE to send a document to an outside party, the file itself stays put inside that customer's own Microsoft 365 tenant. The recipient gets a controlled, branded link to the content - not a downloaded duplicate sitting in someone else's inbox or cloud drive. Access can be scoped, watched, and revoked. There is one copy, and the company that owns it never loses sight of it.
It is a deliberately unglamorous idea, and that is rather the point. eSHARE is not a viral consumer app. It is plumbing for the industries that get sued when a file goes to the wrong place: aerospace and defense, pharmaceuticals, healthcare, and financial services. For them, the difference between sharing a link and sharing a file is the difference between an audit trail and an incident report.
The FounderNick Stamos keeps building the same company
eSHARE's chief executive and founder, Nicholas Stamos, has spent his career circling one obsession: data that leaks. Before eSHARE he helped build Digital Guardian, a data-loss-prevention company, and Phase Forward, a clinical-trial software firm later acquired by Oracle. Across those ventures he has, by the company's own account, raised more than $50 million and created over $1 billion in shareholder value.
That history reads like a straight line. Phase Forward taught him how regulated industries move sensitive information. Digital Guardian taught him how it escapes. eSHARE is the synthesis: a tool that lets the information move without letting it escape. The company began in 2012 under the name nCrypted Cloud, founded by a group of information-security engineers, and later renamed itself around the thing it actually does.
How it worksThe guest account, quietly deleted
Anyone who has administered a corporate Microsoft tenant knows the ritual. To share a file with an outsider, IT provisions a guest account. The partner receives a login they will use once and forget. Security spends the next year auditing thousands of these stale identities. eSHARE's most useful feature is the erasure of that ritual: recipients open shared files without being issued a guest account at all, authenticating with an identity they already have.
The one-copy model
The work happens inside the apps people already use. eSHARE surfaces directly in Teams, SharePoint, OneDrive and Outlook, so an employee shares from the same button they always have. Behind that button sits what the company calls its Trusted Collaboration Fabric - a policy mesh that keeps data in the tenant, maps sharing rules to Microsoft sensitivity labels and data-loss-prevention templates, and records where everything goes. Sharing controls run to more than thirty optional settings, from link expiry to recipient restrictions.
The lineupFour products, one idea
The platform breaks into four pieces, all variations on keeping data home. eSHARE Collaborate is the front door - secure external file sharing, virtual data rooms, content collaboration and secure email, all native to Microsoft 365. eSHARE Govern trims over-permissioned access and readies a tenant for AI. eSHARE Integrate centralizes the sharing policies. eSHARE Analyze turns the audit trail into dashboards that show, often uncomfortably, how far a company's data has actually spread.
The data-room use case is a neat trick worth calling out: eSHARE can spin up a virtual data room dynamically from a single email, letting a deal team collaborate with external parties without standing up a separate repository - and without the files leaving Microsoft 365. It is the classic M&A data room, minus the second data store.
Who buys itLogos that come with lawyers
eSHARE's public customer wall is a roll call of organizations that treat a leaked link as a legal event. Named logos include GE Aerospace, Amgen, Sierra Space, CVS Health, Citizens Financial Group, Boeing, the London Stock Exchange Group, Shell, Kraft Sports + Entertainment and First Horizon. Its compliance coverage reads the same way, spanning CMMC Level 2, NIST 800-171, GxP, 21 CFR Part 11, HIPAA, SOC 2 and FINRA.
There is a reason the defense names cluster here. The U.S. Cybersecurity Maturity Model Certification, or CMMC, is pushing contractors to lock down every controlled file they handle. Compliance panic, it turns out, is a go-to-market engine - and a Microsoft-native tool that keeps regulated files inside the tenant is an easy sentence to put in a procurement memo.
The competitionWhy not just use Box?
The obvious question is what makes this different from Box, Dropbox, Egnyte or Citrix ShareFile. The honest answer is the copy. Those platforms store a duplicate of your file in their cloud; that duplicate is the thing a security team then has to govern. eSHARE's argument is that the cleanest way to secure a shared file is to never let a second one exist. Against traditional virtual data room vendors - Intralinks, Datasite, iDeals - the pitch is similar: the room, without the separate store.
| eSHARE | Typical file-share cloud | |
|---|---|---|
| Where the file lives | Your M365 tenant | Vendor's cloud |
| Second copy created | No | Yes |
| Guest account needed | No | Often |
| Works inside Teams/Outlook | Native | Add-on |
The money & the backersPatient capital, patient market
eSHARE has raised modestly by the standards of enterprise security - a reported total near $8 million, anchored by a $5 million Series A led by Granite Hill Capital Partners. The more interesting line on the cap table is the angel list: Zoom founder Eric Yuan, along with investors Dan Scheinman and Sameet Mehta. The advisory board pulls executives from PTC, Fresenius Medical Care and Rite Aid - the kind of people who have signed off on plenty of enterprise procurement themselves.
The business runs on the familiar B2B SaaS model: subscription licensing, sold direct and through the Microsoft commercial marketplace, sitting on top of a customer's existing Microsoft 365 spend. That last part is the strategic bet - tie yourself to the platform the customer already funds, and become the layer that governs the one thing Microsoft leaves loose.
The expertiseSecurity people, building for security people
eSHARE describes its founding team as information-security engineers, and the product carries that fingerprint. It is not a general collaboration app that added a compliance checkbox; it starts from governance and works outward. Sharing policies map to Microsoft sensitivity labels and DLP templates so a security team can express intent once and have it enforced across Teams, SharePoint, OneDrive and Outlook rather than tool by tool. The company also joined the Microsoft Intelligent Security Association, a marker that Microsoft itself vets the integration, and partnered with Axiomatics to fold fine-grained, attribute-based access control into who can open what.
Secure email rounds out the picture and shows the same instinct at work. Instead of attaching a document to a message that then lives in an unknown number of mailboxes, eSHARE lets the sender email a controlled link to content that stays in the tenant - the same one-copy logic applied to the oldest sharing habit there is. For a compliance officer, the appeal is less about any single feature than about the shape of the whole thing: one place data lives, one trail to audit, one set of rules.
What's nextTeaching the robots to share
The most recent chapter follows the obvious pressure of the moment: AI agents that need to reach files. eSHARE has extended its fabric to what it calls agentic AI workflows, letting automated agents collect, analyze and communicate over shared content - while the underlying data stays inside Microsoft 365. The same principle, pointed at a new kind of user. If the last decade's problem was employees sending copies out the door, the next one is software doing it faster.
None of it is flashy, and eSHARE seems fine with that. The company found the one workflow every large enterprise quietly hates, planted itself inside the software those enterprises already run, and sold to the industries where a mistake is not a headache but a filing. Whether that is a big business or a durable one is still being written. The idea underneath it is small enough to fit on a sticker, and stubborn enough to have kept its founder busy for twenty years.