Microsoft 365

Microsoft 365 is a cloud-based productivity and collaboration suite built around the familiar Office applications (Word, Excel, PowerPoint, Outlook) plus cloud services like Teams, SharePoint, OneDrive, and Exchange Online. It covers email, file storage and sharing, video conferencing, chat, calendar, task management, and document collaboration.

The target market spans from small businesses through to the largest enterprises and government agencies. For SMBs, the core value is getting business email, cloud storage, and the Office desktop apps in a single subscription. For larger organisations, it extends into compliance tooling, device management (Intune), advanced security (Defender), and workflow automation (Power Automate).

Microsoft has been heavily investing in AI through Copilot, which adds AI-assisted writing, data analysis, and meeting summarisation across the suite. This is being bundled into more plans over time rather than remaining a standalone add-on.

Microsoft 365 uses a per-user, per-month subscription model with annual billing discounts. There is no genuine free tier for business use, though consumers can use basic web versions of Office apps with a free Microsoft account.

For small and mid-sized businesses, the main tiers are Business Basic (around US$6-7 per user per month for web and mobile Office apps, email, Teams, and 1 TB OneDrive), Business Standard (around US$12-14 per user per month, adding full desktop Office apps), and Business Premium (around US$22 per user per month, adding security and device management). Price increases are taking effect in July 2026 for the Basic and Standard tiers.

Enterprise plans (E1, E3, E5) exist for larger organisations, scaling up to include advanced compliance, analytics, voice capabilities, and the full security suite. The jump from E3 to E5 is significant in both features and cost.

The key thing to understand is that Business Basic does not include desktop Office apps. If your team needs Word, Excel, and PowerPoint installed on their computers, Business Standard is the minimum.

Vendor lock-in with Microsoft 365 is high, and this is the single most important strategic consideration. Once your business builds email workflows, SharePoint sites, Teams channels, Power Automate flows, and custom Graph integrations, switching to another platform becomes a major undertaking.

Email is the most portable piece. PST export is widely supported, and most competing platforms can import it. SharePoint content can be migrated with effort, though metadata, permissions, and configurations need rebuilding. Teams is the stickiest component. There is no standardised export format for conversation history, and rebuilding channel structures, bots, and workflows on another platform is substantial work.

The operational setup is where the real lock-in lives. Years of configured mail rules, conditional access policies, compliance settings, retention policies, and Power Automate workflows do not transfer. You are rebuilding your entire digital workplace from scratch.

This does not mean you should not use Microsoft 365. For most businesses already in the Microsoft ecosystem, the lock-in is an acceptable trade-off for the breadth and quality of the platform. But go in with clear eyes: treat this as a long-term commitment, not a tool you will swap out next year.

Microsoft was founded in 1975 by Bill Gates and Paul Allen and is headquartered in Redmond, Washington. It is publicly traded on NASDAQ (MSFT) with a market capitalisation of approximately US$3 trillion, making it one of the two or three most valuable companies on the planet. The company employs around 228,000 people.

Financially, Microsoft is in exceptional shape. Revenue for fiscal year 2025 was US$282 billion, up 15% year-on-year, driven by cloud services (Azure) and AI investments. Growth shows no signs of slowing.

Microsoft 365 specifically launched as Office 365 in June 2011 and was rebranded to Microsoft 365 in April 2020. That is 15 years of continuous operation as a cloud productivity suite. It has hundreds of millions of commercial users worldwide. This is about as stable a platform as you will find in the software industry.

Microsoft Graph is the single unified API for Microsoft 365, and it is genuinely impressive in scope. It provides access to email, calendar, contacts, files (OneDrive/SharePoint), Teams, users, groups, and dozens of other services through one consistent REST endpoint. The API is mature and well-documented for mainstream scenarios.

Rate limits are where things get complicated. There is no single global limit that applies everywhere. Each service (Exchange, SharePoint, Teams, etc.) has its own throttling rules, and they vary significantly. SharePoint and OneDrive are particularly aggressive, throttling at sustained rates above one request per second. Exchange allows more headroom for most operations. The throttling algorithm is opaque, which makes it hard to predict exactly when you will hit walls.

In practice, this means your integrator needs to build retry logic and respect throttle headers from day one. Small-volume integrations (syncing a few mailboxes, reading calendar events) work smoothly. High-volume operations (migrating thousands of files, bulk-syncing email) require careful engineering with batching, queuing, and backoff strategies.

Microsoft is currently retiring several legacy APIs in a compressed timeframe. Exchange Web Services shuts down fully in April 2027, Azure AD Graph was retired in June 2025, and the Graph CLI and Toolkit were deprecated in August 2025. If you have existing integrations on any of these, budget time for migration.

Microsoft Graph supports change notifications (webhooks) for most major resources including mail, calendar, contacts, Teams messages, and OneDrive files. Setup is straightforward through the subscriptions API. Subscriptions have expiry times that vary by resource (up to 3 days for most, shorter for some) and need to be renewed. Webhook delivery is generally reliable, but you should implement fallback polling for critical workflows.

Getting your data out of Microsoft 365 is possible but varies by service. Email is the most portable component. You can export mailboxes to PST format, which is widely supported by other email platforms. SharePoint and OneDrive files can be synced locally or exported through the API, though large migrations take time due to throttling.

Teams conversation history is the most locked-in component. There is no clean, standardised way to export Teams chat and channel history to a format another platform can import. Microsoft has committed to improving this under EU data portability regulations, but it is still a weak point.

Microsoft 365 does not include native point-in-time backup and restore. The recycle bin has a 93-day window, and retention policies are compliance tools, not backup tools. Many organisations use third-party backup solutions to fill this gap.

Practically speaking, vendor lock-in is moderate to high. The data itself is mostly accessible, but the operational setup, including mail rules, SharePoint configurations, Teams channels, Power Automate workflows, and permission structures, does not transfer. If you have spent years building out your Microsoft 365 environment, switching to Google Workspace or another platform is a project measured in months.

Documentation is generally good for mainstream integration scenarios. Microsoft Learn is well-structured with tutorials, API references, and conceptual guides. Graph Explorer, a browser-based tool for testing API calls, is genuinely useful and well-regarded by developers.

The free developer sandbox is a strong point. The Microsoft 365 Developer Program provides a full E5 tenant with 25 user licences, pre-loaded sample data, and auto-renewal if you are actively developing. This is more generous than most platforms offer for testing.

The main pain points are around the SDKs and the pace of change. Official SDKs exist for .NET, Java, Python, JavaScript, Go, and PHP, but they are auto-generated using Microsoft Kiota tool. This means quality can be inconsistent, with reports of bugs shipping in releases that were not adequately tested. Many experienced developers prefer using the REST API directly rather than relying on the SDKs.

The other frustration is maintenance burden. With Azure AD Graph, Exchange Web Services, Graph CLI, and Graph Toolkit all being retired in a short window, developers working with Microsoft 365 describe feeling like they are constantly running to stay in place. The API itself is stable, but the ecosystem around it is in flux.