Why Microsoft Dominates DoD Email
Scott Sanders, chief growth officer at Forterra, on the defense tech startup playbook
Microsoft’s grip on DoD email shows how hard it is to dislodge an incumbent when email is tied to identity, security controls, and the rest of the software bundle. In practice, DoD users are not just choosing an inbox. They are choosing login, document tools, chat, device management, archive, and compliance as one stack. Google won the right security certifications, but even the Army’s Google Workspace pilot drew limited usage and was shut down in favor of Army 365.
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Microsoft’s advantage is structural, not just product quality. Government versions of Microsoft 365 are built specifically for GCC, GCC High, and DoD environments, and Teams and adjacent tools are sold as part of that same compliance ready stack. That makes Outlook sticky because replacing email often means replacing the broader operating system for office work.
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Google has cleared major trust hurdles. Google Workspace has FedRAMP High authorization, and Google Cloud supports DoD IL5 workloads. But clearance to sell is different from winning deployment. The Army said its Google Workspace pilot reached fewer than 16% of the intended military audience, then decommissioned those accounts on February 28, 2025 and moved users to Army 365.
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This is the same pattern seen in enterprise software more broadly. Bundled collaboration suites can overpower point improvements, because distribution and switching cost matter more than a somewhat better tool. Email is especially hard because it sits at the center of identity and daily workflow, which is why newer products usually layer on top of Outlook or Gmail instead of replacing them outright.
The path forward in defense collaboration is likely more consolidation around secure suites, not a clean sheet swap of inbox providers. New entrants will win by solving mission specific workflows on top of the incumbent stack, or by offering a step change in cost or capability, not by shipping a slightly better email client.