# Microsoft Defender for Office 365 vs MX Layer Outbound Email Filtering: 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). [MX Layer Outbound Email Filtering](https://cybersectools.com/tools/mx-layer-outbound-email-filtering) is a commercial [email security platforms](https://cybersectools.com/categories/email-security-platforms) solution by [MX Layer](https://cybersectools.com/companies/mx-layer). 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 | MX Layer Outbound Email Filtering |
|---|---|---|
| Pricing model | Commercial | Commercial |
| Category | Email Security Platforms | Email Security Platforms |
| Verified | No | No |
| Deployment type | Cloud | Cloud |
| Company size fit | SMB, Mid-Market, Enterprise | Startup, SMB, Mid-Market, Enterprise |
| Company | Microsoft | MX Layer |
| Headquarters | – | – |

### Use cases and capabilities

| | Microsoft Defender for Office 365 | MX Layer Outbound Email Filtering |
|---|---|---|
| Microsoft 365 | Yes | – |
| Content Filtering | – | Yes |
| DKIM | – | Yes |
| DMARC | – | Yes |
| SPF | – | Yes |
| Spam Prevention | – | Yes |

### Core features

**Microsoft Defender for Office 365**

10 features listed. Sign in on the page to see them.

**MX Layer Outbound Email Filtering**

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.

**MX Layer Outbound Email Filtering**

No integrations listed.

## Which one fits you

Based on what each listing shows: deployment, company size, price and open source.

- [MX Layer Outbound Email Filtering](https://cybersectools.com/tools/mx-layer-outbound-email-filtering) fits if you are a startup.

## Microsoft Defender for Office 365 vs MX Layer Outbound Email Filtering FAQ

Common questions when comparing Microsoft Defender for Office 365 vs MX Layer Outbound Email Filtering for email security platforms.

### What is the difference between Microsoft Defender for Office 365 and MX Layer Outbound Email Filtering?

**Microsoft Defender for Office 365**: Email and collaboration security for Microsoft 365 environments. Built by Microsoft.

**MX Layer Outbound Email Filtering**: Outbound email filtering platform for spam prevention and IP reputation mgmt. Built by MX Layer.

The table above shows where their features, integrations, deployment and company size fit differ.

### Who makes Microsoft Defender for Office 365 and MX Layer Outbound Email Filtering?

**Microsoft Defender for Office 365** is made by Microsoft. **MX Layer Outbound Email Filtering** is made by MX Layer. 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 MX Layer Outbound Email Filtering?

Often, yes. Microsoft Defender for Office 365 and MX Layer Outbound Email Filtering 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 SmarterTools SmarterMail](https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-smartertools-smartermail)
- [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 SpamTitan Gateway](https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-spamtitan-gateway)
- [MX Layer Outbound Email Filtering vs SmarterTools SmarterMail](https://cybersectools.com/compare/mx-layer-outbound-email-filtering-vs-smartertools-smartermail)
- [MX Layer Outbound Email Filtering vs Infonaligy Proofpoint Email Security](https://cybersectools.com/compare/infonaligy-proofpoint-email-security-vs-mx-layer-outbound-email-filtering)
- [MX Layer Outbound Email Filtering vs SpamTitan Gateway](https://cybersectools.com/compare/mx-layer-outbound-email-filtering-vs-spamtitan-gateway)

## Alternatives to each

- [See all Microsoft Defender for Office 365 alternatives](https://cybersectools.com/alternatives/microsoft-defender-for-office-365)
- [See all MX Layer Outbound Email Filtering alternatives](https://cybersectools.com/alternatives/mx-layer-outbound-email-filtering)

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Source: https://cybersectools.com/compare/microsoft-defender-for-office-365-vs-mx-layer-outbound-email-filtering

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 MX Layer Outbound Email Filtering: 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