# Microsoft Defender for Office 365 vs SmarterTools SmarterMail: side-by-side comparison (2026) [Microsoft Defender for Office 365](https://cybersectools.com/tools/microsoft-defender-for-office-365) is a commercial [email security platforms](https://cybersectools.com/categories/email-security-platforms) solution by [Microsoft](https://cybersectools.com/companies/microsoft). [SmarterTools SmarterMail](https://cybersectools.com/tools/smartertools-smartermail) is a commercial [email security platforms](https://cybersectools.com/categories/email-security-platforms) solution by [SmarterTools](https://cybersectools.com/companies/smartertools). Features, integrations, deployment and the company behind each one, side by side. ## Our take What our shortlists say about the one we picked. ### [Microsoft Defender for Office 365](https://cybersectools.com/tools/microsoft-defender-for-office-365) Best for: Teams running Microsoft 365 It is on the list because it is built into Microsoft 365, and many companies already own it through their license, so the buying question is often settled before you start. That makes it the natural first layer if you run Microsoft 365. Decide whether it covers your risk alone or needs a second product beside it, since it is built to work with other email security products. From [Best Email Security Solutions for Business](https://cybersectools.com/shortlists/best-email-security-platforms), Fall 2026. Reviewed by [Nika (Nikoloz) Kokhreidze](https://cybersectools.com/about). Need the answer fast? [Best Email Security Solutions for Business](https://cybersectools.com/shortlists/best-email-security-platforms) picks Proofpoint Core Email Protection, Microsoft Defender for Office 365, Mimecast Advanced Email Security and 4 more. ## Side-by-side comparison | | Microsoft Defender for Office 365 | SmarterTools SmarterMail | |---|---|---| | Pricing model | Commercial | Commercial | | Category | Email Security Platforms | Email Security Platforms | | Verified | No | No | | Deployment type | Cloud | On-Premises | | Company size fit | SMB, Mid-Market, Enterprise | Startup, SMB, Mid-Market, Enterprise | | Company | Microsoft | SmarterTools | | Headquarters | – | – | ### Use cases and capabilities | | Microsoft Defender for Office 365 | SmarterTools SmarterMail | |---|---|---| | Microsoft 365 | Yes | – | | Spam Prevention | – | Yes | | Linux | – | Yes | | Windows | – | Yes | | DKIM | – | Yes | | SPF | – | Yes | | DMARC | – | Yes | ### Core features **Microsoft Defender for Office 365** 10 features listed. Sign in on the page to see them. **SmarterTools SmarterMail** 10 features listed. Sign in on the page to see them. ### Integrations **Microsoft Defender for Office 365** 4 integrations listed. Sign in on the page to see them. **SmarterTools SmarterMail** 6 integrations listed. Sign in on the page to see them. ## Which one fits you Based on what each listing shows: deployment, company size, price and open source. - [Microsoft Defender for Office 365](https://cybersectools.com/tools/microsoft-defender-for-office-365) fits if you want a cloud product. - [SmarterTools SmarterMail](https://cybersectools.com/tools/smartertools-smartermail) fits if you need to run it on your own servers and you are a startup. ## Microsoft Defender for Office 365 vs SmarterTools SmarterMail FAQ Common questions when comparing Microsoft Defender for Office 365 vs SmarterTools SmarterMail for email security platforms. ### What is the difference between Microsoft Defender for Office 365 and SmarterTools SmarterMail? **Microsoft Defender for Office 365**: Email and collaboration security for Microsoft 365 environments. Built by Microsoft. **SmarterTools SmarterMail**: Email server with antispam, antivirus, and security features for Linux/Windows. Built by SmarterTools. The table above shows where their features, integrations, deployment and company size fit differ. ### Who makes Microsoft Defender for Office 365 and SmarterTools SmarterMail? **Microsoft Defender for Office 365** is made by Microsoft. **SmarterTools SmarterMail** is made by SmarterTools. The vendor behind a product decides its roadmap, support, and longevity, so check each company's profile before you commit. ### Is Microsoft Defender for Office 365 a good alternative to SmarterTools SmarterMail? Often, yes. Microsoft Defender for Office 365 and SmarterTools SmarterMail are both Email Security Platforms products. Use the table above to see where features, deployment and company size fit differ. ## Related comparisons - [Microsoft Defender for Office 365 vs MX Layer Outbound Email Filtering](https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-mx-layer-outbound-email-filtering) - [Microsoft Defender for Office 365 vs Infonaligy Proofpoint Email Security](https://cybersectools.com/compare/infonaligy-proofpoint-email-security-vs-microsoft-defender-for-office-365) - [Microsoft Defender for Office 365 vs PowerDMARC Hosted DMARC](https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-powerdmarc-hosted-dmarc) - [SmarterTools SmarterMail vs MX Layer Outbound Email Filtering](https://cybersectools.com/compare/mx-layer-outbound-email-filtering-vs-smartertools-smartermail) - [SmarterTools SmarterMail vs Infonaligy Proofpoint Email Security](https://cybersectools.com/compare/infonaligy-proofpoint-email-security-vs-smartertools-smartermail) - [SmarterTools SmarterMail vs PowerDMARC Hosted DMARC](https://cybersectools.com/compare/powerdmarc-hosted-dmarc-vs-smartertools-smartermail) ## Alternatives to each - [See all Microsoft Defender for Office 365 alternatives](https://cybersectools.com/alternatives/microsoft-defender-for-office-365) - [See all SmarterTools SmarterMail alternatives](https://cybersectools.com/alternatives/smartertools-smartermail) --- Source: https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-smartertools-smartermail For AI agents: each product above has its own Markdown page (add .md to its URL, for example https://cybersectools.com/tools/microsoft-defender-for-office-365.md). Every CybersecTools shortlist is listed at https://cybersectools.com/shortlists.md. More on Microsoft Defender for Office 365 and SmarterTools SmarterMail: funding, momentum, hiring and news, plus the full product and company record, are available through the Mandos MCP Server (paid plans), which connects to AI assistants: https://mandos.io/mcp?utm_source=cybersectools.com&utm_medium=compare-md