Microsoft Defender for Office 365 vs Mimecast Advanced Email Security comparison

Microsoft and Mimecast are both solutions in the Secure Email Gateway (SEG) category. Microsoft is ranked #2 with an average rating of 8.5, while Mimecast is ranked #3 with an average rating of 8.5. Additionally, 96% of Microsoft users are willing to recommend the solution, compared to 91% of Mimecast users who would recommend it.

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Executive SummaryUpdated on Jun 2, 2026

Mimecast Advanced Email Security and Microsoft Defender for Office 365 compete in the email protection category. Microsoft Defender for Office 365 has a slight edge with its integration and comprehensive feature set, providing robust threat prevention and post-delivery cleanup.

Features: Mimecast offers advanced email protection features such as sandboxing of email attachments, spam filtering, and adaptable filtering capabilities. These features provide seamless integration with existing systems and ensure mailbox continuity. Microsoft Defender for Office 365 includes Safe Links, Safe Attachments, and Threat Explorer, which offer real-time protection against zero-day threats and provide detailed threat investigation capabilities.

Room for Improvement: Mimecast could enhance detection rates and the usability of its admin console, and improve technical support response times. Reducing false positives and streamlining phishing reporting would also be beneficial. Defender for Office 365 can improve by optimizing false-positive tuning, providing flexible policy configuration, and enhancing reporting capabilities, benefiting from greater product suite integration and streamlined policy management.

Ease of Deployment and Customer Service: Mimecast supports deployment in public and private clouds but has inconsistent technical support, with reliance on knowledge-base articles. Microsoft Defender for Office 365 offers flexible deployment options, particularly in hybrid cloud environments, and provides a comprehensive support experience, though it could be more proactive.

Pricing and ROI: Mimecast is considered expensive, with per-user costs and additional fees for services like support and data extraction. Despite this, it offers a robust return on investment. Microsoft Defender for Office 365 provides reasonable value when bundled with Office 365 E5, though standalone pricing may seem higher. Its licensing model can be confusing, but its integration and features offer good value within the Microsoft ecosystem.

To learn more, read our detailed Microsoft Defender for Office 365 vs. Mimecast Advanced Email Security Report (Updated: August 2026).

Buyer's Guide

Microsoft Defender for Office 365 vs. Mimecast Advanced Email Security

August 2026

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Review summaries and opinions

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

Categories and Ranking

Cloudflare One

Featured Reviews

Cobe Van Coller

Network Architect at IP Dimension

Cloud security has improved remote access and has reduced costs for smaller client sites

I have used Cloudflare One's Identity-Aware Proxy, and it is quite straightforward from what I have seen so far. The app registration on the Azure side integrates fully into Cloudflare, and I am very satisfied with that part because it is easy to set up. The integration of Cloudflare One's Secure Web Gateway and Zero Trust Network Access works without any issues. That part is pretty automatic, and if you complete the rest of the setup, it comes together by itself with no issues from my side. What makes it nice is that we can actually start replacing on-site firewalls at this stage for the smaller clients because it does not matter if they go to a coffee shop or work from home; they are still secured by the same connection. The hops get shorter and you get better latency. We have done testing to see if it is better. One thing that we did notice with our proof of concept with our current client is that they have people connecting from the UK. When they used their previous VPN solution, uploading CAD drawings and other files to the server took a long time. They mentioned that it is much quicker on Cloudflare One's solution. I definitely believe that is part of the improved performance, and I am satisfied with that as well. What is nice about Cloudflare One is that it makes the setup easier and also easier to train technicians to maintain it. Compared to legacy systems, we do not need to get fancy firewalls in place that are costly. That is definitely also a cost-saver with Cloudflare One.

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Emeka Ndulu

Cloud Solutions Architect at a tech services company with 201-500 employees

Improves threat visibility and response while reducing manual tasks and training users against phishing

I appreciate the attack simulation feature whereby I get to train users and educate them on how to identify phishing emails and spam emails, as well as the anti-spam protection. It gives me visibility into my threat environment and threat landscape to ensure that I am one step ahead of any likelihood of threats within my environment. I get to detect it and respond, so the threat intelligence is very effective. Microsoft security solutions save my time. It saves money because once I protect my environment, I don't lose money. It has decreased my detection time and my time to respond.

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Avinash Mishra

Manager - EUC at Finthrive

Advanced email filtering has blocked massive spam volumes and prevents unauthorized data leaks

Improvements for Mimecast Advanced Email Security include enhancing the user interface and accessibility, particularly regarding admin capabilities to add or modify user accounts. Streamlining this could improve overall usability and security management for users. Reporting is another area needing improvement in Mimecast Advanced Email Security, as the reports provided are not very easy to decipher. With artificial intelligence being integrated into various tools including Mimecast Advanced Email Security, I believe there is potential to enhance functionality, enabling users to ask specific questions and retrieve concise answers instead of overwhelming data. I choose a nine for Mimecast Advanced Email Security because improvements such as better user interface and artificial intelligence integration features would greatly enhance its usability. While no tool is perfect, these adjustments could greatly elevate Mimecast Advanced Email Security's capabilities.

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Quotes from Members

We asked business professionals to review the solutions they use. Here are some excerpts of what they said:

Pros

"It's the endpoint exposition. We don't need to expose our VPN server to the internet and need a zero-test solution. I can apply some conditional access to the endpoint that's connecting to our network to check their security policies or the security condition of their workstation. Once the workstation is trying to connect to my internal network, then I would like to check the discrete condition of these endpoints that are trying to access my internal network. We created some conditional access. We have CrowdStrike, to check if the CrowdStrike is installed, to check if it's updated, and to check for Windows updates. We created some conditional policies to check it."

"Cloudflare, in my opinion, was easy to implement."

"Using Cloudflare One makes my work quite easy because for DDoS protection, all I need to do is understand the OSI model and click; it makes it easier than trying to write a command line or use a Linux command."

"The tool also offers good scalability, and the dashboard, along with real-time analytics, is very good."

"The solution has different options that can be used to differentiate DDoS attacks."

"I'm very satisfied with the environment and the dashboard."

"Cloudflare is by far the most effective solution that I have come across."

"Cloudflare Access is a stable solution."

More Cloudflare One pros

"The most valuable feature of Microsoft Defender for Office 365 is its spam filter."

"I would say that 90% of the spam and phishing attack emails get blocked right off the bat."

"The feature of Microsoft Defender for Office 365 that I like the most is probably the email features specifically, because those are the ones that a typical end user will accidentally click on a link not knowing what it is, and it'll catch it, and then it'll feed it over to Defender and stop the attack from happening before it actually can."

"Does a thorough job of examining email and URLs for malicious content."

"Microsoft so far has been good; we haven't faced any kind of disruption or anything else, it's a good product and good platform, I must say, and overall it's a good product and good service and we haven't dealt with bugs or glitches."

"The deployment capability is a great feature."

"Microsoft Defender for Office 365 helps people to work remotely. It is a secure solution. We don't need to use our company's computers or get VPN connections to the networks. I can control how they share screens and what they send to the devices. It keeps our organizations confidential and sensitive information safe."

"Threat Explorer is an invaluable tool for me, and it plays a crucial role in helping me discern the origins of various email campaigns, pinpointing where they emanate from, and identifying the individuals within our organization who are affected."

More Microsoft Defender for Office 365 pros

"The positive impact of Mimecast Advanced Email Security on our organization is evident in how it has drastically reduced spam emails and improved our data security."

"The security on offer is very good."

"The solution's performance is good."

"I would rate Mimecast Email Security a nine out of ten."

"It's good, it keeps the spam out."

"Mimecast certainly helped my customers reduce phishing emails."

"URL inspection works pretty well."

"The platform's most valuable features are journaling and email archiving, effectively stopping phishing attacks."

More Mimecast Advanced Email Security pros

Cons

"Automation could be improved where you can easily add a TLS and SSL certificate to an application or web app if the developer did not include it."

"I would like them to include a VPN feature to provide a secure connection to the data center."

"The free plan has limitations. For example, I can only set up three rules, and the application firewall is unavailable."

"Feedback could be enhanced."

"For the topic of improvement, providing some training material is one of my suggestions."

"Our subscription plan for the solution has a limitation of bot signatures."

"Cloudflare DDoS has poor technical support."

"Operating and tuning the product is difficult."

More Cloudflare One cons

"The UI needs to be more user-friendly."

"We are always looking for others tools to increase automation on tasks. There can be better integration with other solutions, such as PowerPoint and email."

"Microsoft security solutions work as expected. They are constantly updating the solutions to make them better. At the same time, the changes can impact a customer's environment, and we need to adjust settings. Sometimes we aren't aware of the changes, and nothing is pushed from the backend automatically."

"I am generally satisfied with how it currently is. If I could improve anything, I would reduce the cost."

"The custom alerts have to improve a lot."

"The XDR dashboard has room for improvement."

"The cost of Security Copilot is up there right now, and I think it needs to come down for more people to adopt."

"One area for improvement is integration. For example, when it comes to external SaaS platforms, we were not able to get a lot of information on integrations with such apps for security and authentication."

More Microsoft Defender for Office 365 cons

"Its pricing can be improved. It is a bit expensive."

"External security features need improvement."

"The solution's console interface was recently changed for the admins, but the previous one was much better because we could open tabs on it."

"I'd like to have better support from the product in the future."

"The price could be better, it should be reduced."

"The system is not user-friendly because you have to create policies that are mapped in a dictionary."

"This solution can be frustrating. It blocks many things that should be going through."

"Improvements for Mimecast Advanced Email Security include enhancing the user interface and accessibility, particularly regarding admin capabilities to add or modify user accounts."

More Mimecast Advanced Email Security cons

Pricing and Cost Advice

"The pricing is somewhere in the middle. I would rate the pricing a seven out of ten."

"The solution is not that expensive."

"The price tag is no longer $200,000, but rather $300,000 to $400,000. It's twice."

"The solution's pricing lacks transparency."

"The prices are slightly expensive."

"My company has to make yearly payments towards the licensing costs attached to the solution. There are no hidden charges apart from the licensing costs of the solution."

"The pricing of the solution is cheap. The licensing cost is also very low. I rate the cost and pricing a three out of ten."

"Cloudflare Zero Trust Platform's pricing is good."

"For large enterprise organizations, they can definitely afford it, but for small and medium organizations, they might struggle to cover the expenses."

"For licensing, it's usually a yearly package for customers who are subscribed to Office 365, but they can also pay on a monthly basis."

"It's a user-base subscription."

"The pricing is normal. Considering its popularity, it's not overpriced."

"Compared to other brands, Microsoft Defender for Office 365's pricing is competitive."

"I know that the product is incredibly expensive."

"I was working in the government and it was too expensive for us to use our Microsoft products."

"Microsoft Defender for Office 365 comes with Microsoft Windows. It is free with the operating system."

More Microsoft Defender for Office 365 pricing and cost advice

"Compared to the other products in the market, it is neither cheap but nor very expensive. I would rate it somewhere in the middle, 5 out of 10."

"The customers can select the license packages as per their requirements."

"It's an expensive solution."

"It is a bit expensive."

"On a scale of one to ten, where one is cheap, and ten is expensive, I rate the pricing a ten."

"I'm always going to say the price needs to be lower, but it's reasonable."

"Compared to the other solutions in the market, Mimecast Email Security with Targeted Threat Protection's pricing is fine."

"The licensing costs are per-user for the product that you get with them."

More Mimecast Advanced Email Security pricing and cost advice

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Answers from the Community

Hugues Matingou

Senior System Engineer at AfDB

May 4, 2023

Is Defender for Office 365 enough? Or should we be using a product like Mimecast?

In my opinion, all gateways including Mimecast or Defender for O365 or ProofPoint work hand-in-hand in their respective mechanics and algorithms built. And definitely has its own advantages. However, I have been using it for my customers' MDO which is far better. I would say relying on gateways is important but at the same time USER education and reporting back to the IT administrator far impor...

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TyroneLim

Senior IT Security Specialist at a tech services company with 1,001-5,000 employees

Apr 25, 2023

Greetings Matingou, Defender for O365 I would say would suffice as it has all the tools included in Mimecast in just one single tool, may take some time to navigate at first as it gives a lot of information in just one tool but once you know your way around, you will be able to have good visibility on your email threats landscape by provides a range of protections against email-based threats such as spam, phishing, malware, and etc. It also includes features such as URL protection and attachment scanning to prevent users from clicking on malicious links or downloading harmful files. but on the other hand, Mimecast might be needed, if you require compliance measures, including data loss prevention, archiving, and encryption. It also provides greater visibility and control over email security, allowing you to monitor and manage threats in real-time. Hope this helps.

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Bala Krishna

IT Manager at vTech4U

May 4, 2023

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Top Industries

By visitors reading reviews

Construction Company

19%

Comms Service Provider

10%

Outsourcing Company

Financial Services Firm

Computer Software Company

11%

Manufacturing Company

Financial Services Firm

Comms Service Provider

Computer Software Company

10%

Financial Services Firm

Construction Company

Outsourcing Company

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	10
Midsize Enterprise	1
Large Enterprise	12

By reviewers
Company Size	Count
Small Business	24
Midsize Enterprise	11
Large Enterprise	32

By reviewers
Company Size	Count
Small Business	19
Midsize Enterprise	12
Large Enterprise	19

Questions from the Community

What is your experience regarding pricing and costs for Cloudflare Zero Trust Platform?

Pricing is competitive. Akamai is more expensive, in my view.

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What needs improvement with Cloudflare Zero Trust Platform?

In my opinion, Cloudflare One can be improved mainly through compatibility, as the integration should be much simpler...

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What is your primary use case for Cloudflare Zero Trust Platform?

Cloudflare One's primary use case for my organization is to protect servers and to provide remote access with the VPN...

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What is your experience regarding pricing and costs for Microsoft Defender for Office 365?

My experience with pricing, setup, and licensing is that it's actually quite reasonable even on the licensing side as...

See all answers

What needs improvement with Microsoft Defender for Office 365?

I think Microsoft Defender for Office 365 can be improved by creating more educational pieces about not just looking ...

See all answers

What is your primary use case for Microsoft Defender for Office 365?

My main use cases for Microsoft Defender for Office 365 include email hygiene.

See all answers

What is your experience regarding pricing and costs for Mimecast Email Security with Targeted Threat Protection?

Do you know anything about the pricing and cost of the Mimecast Email Security?

See all answers

What needs improvement with Mimecast Email Security with Targeted Threat Protection?

There is room for improvement since new threats are emerging. Considering the availability of new features would be w...

See all answers

What is your primary use case for Mimecast Email Security with Targeted Threat Protection?

I have been working with Mimecast Email Security.

See all answers

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Product Reports

Buyer's Guide

Cloudflare One

August 2026

Download Cloudflare One product report

Buyer's Guide

Microsoft Defender for Office 365

July 2026

Microsoft Defender for Office 365 report

Download Microsoft Defender for Office 365 product report

Buyer's Guide

Mimecast Advanced Email Security

July 2026

Download Mimecast Advanced Email Security product report

Also Known As

Cloudflare Area 1 Email Security, Cloudflare Bot Management, Cloudflare Gateway, Cloudflare Zero Trust Platform, Cloudflare DDoS, Cloudflare SASE & SSE Platform

MS Defender for Office 365

Mimecast Email Security with Targeted Threat Protection, Mimecast Web Security, Mimecast Mailbox Continuity, Email and Collaboration Threat Protection

Overview

Cloudflare One is a comprehensive platform for security, performance, and connectivity. It provides features like rate limiting, DDoS protection, and application access, tailored to enhance user experience while securing internet access and accelerating communications.

Designed to integrate security measures with ease of use and scalability, Cloudflare One offers a secure web gateway and zero trust network access. These features ensure seamless setup and operation, making connectivity reliable and protected. Users appreciate its integrated console, intuitive interface, and the ability to manage risk effectively. It offers straightforward deployment, improves latency, and boasts cost-effectiveness. While its onboarding process and documentation need enhancement, its value in content delivery and application shielding is notable. Despite challenges in integrating Cloudflare Access with existing VPNs and the need for better automation and support, it remains vital for DNS and infrastructure protection.

What features make Cloudflare One stand out?

Rate Limiting: Controls the traffic rate to prevent abuse.
DDoS Protection: Shields applications from distributed denial-of-service attacks.
Secure Web Gateway: Provides secure internet access with seamless operation.
Zero Trust Network Access: Ensures secure, application-based connectivity without relying on traditional VPNs.
Access for Connectivity: Facilitates access to internal applications securely.

What benefits should users look for in reviews?

Security: Robust measures for DNS and browsing protection.
Performance: Enhanced site accessibility and communication speed.
Cost-Effectiveness: Offers competitive pricing for its features.
Ease of Deployment: Straightforward and efficient setup process.

In industries like finance, retail, and technology, Cloudflare One is crucial for enabling secure remote access and protecting web applications against dynamic threats. It supports compliance access policies and enhances content delivery, playing a key role in safeguarding digital infrastructure.

Cloudflare

Microsoft Defender for Office 365 offers real-time email security, enhancing threat detection through integration within the Microsoft ecosystem. Its user-friendly interface and central management streamline operations, providing robust protection against phishing, ransomware, and malware.

Defender for Office 365 is focused on efficiently securing email communication by safeguarding against phishing, malware, and spam threats. With its strong integration with other Microsoft services, it is tailored to improve endpoint security and identity protection. Its centralized management tools simplify threat prioritization, while the automated threat response capabilities ensure swift actions against potential risks. Organizations leverage its capabilities to efficiently manage their cybersecurity efforts, particularly in remote work environments, while maintaining a secure system across Office 365 applications and Azure-hosted services.

What are the key features?

Real-time Email Protection: Continuously monitors and protects email communications.
Safe Attachments and Links: Scans attachments and links for potential threats.
Anti-Phishing Measures: Provides tools to detect and block phishing attempts.
Integration with Microsoft Services: Seamlessly connects with other Microsoft applications for enhanced security.
Automated Threat Responses: Activates immediate responses to detected threats.

What benefits should users expect from reviews?

Time Savings: Automates processes to reduce manual threat management efforts.
Improved Cybersecurity: Strengthens organizational defenses against various cyber threats.
Efficient Remote Work: Enhances protection for remote teams and virtual collaborations.
Comprehensive Coverage: Extends protection across Office 365 and Azure services.

Implementations of Defender for Office 365 vary across industries, optimizing email security for sectors such as finance, healthcare, and education. In finance, it aids in protecting sensitive financial data from phishing and fraud. Healthcare benefits from secure communications, ensuring patient data privacy. Educational institutions use it to maintain secure virtual learning environments against cyber threats.

Microsoft

Mimecast Email Security protects organizations against phishing, malware, business email compromise, and impersonation attacks, with detection built on 20 years of experience and over 1.3 billion emails inspected daily. It's available as a secure email gateway (MX-based) for full control over complex, multi-region environments, or via API integration with Microsoft 365, which deploys in hours with no MX changes. Administrators get a single console for policy management, monitoring external communications, and customizing configurations, and can pair it with Mimecast Cloud Archive for long-term email retention and compliance.

What key features should users explore?

Sandboxing: Full emulation sandboxing and AI-driven static analysis detect threats in attachments before delivery.
Spam and Phishing Protection: Multi-layered detection catches both payload-based attacks and payloadless, socially-engineered BEC attempts.
URL Inspection: Computer Vision AI analyzes destination pages to catch phishing and brand impersonation.
API Deployment Option: Deploys in hours without MX or mail flow changes, with 30-day historical scanning to show threats your current defenses missed.
Email Archiving (via Cloud Archive): Secure long-term storage supporting compliance needs.

What benefits can impact ROI?

Regulatory Compliance: Supports adherence to standards like HIPAA through retention and monitoring.
Integration: Deep integration with Microsoft 365, deployable as a gateway or via API depending on your environment.
Rapid Time to Value: API deployment proves protection value in hours, before any infrastructure commitment.
Threat Prevention: Detection engines refined daily against 1.3 billion emails, trusted by 42,000 customers globally.

Industries and use cases

Mimecast Email Security is used across industries, including healthcare and finance, to secure inbound and outbound communications and support compliance requirements. Enterprises use it as a gateway, an API-based layer on top of Microsoft 365, or both, depending on how much control versus deployment speed they need.

Mimecast

Sample Customers

23andMe

Microsoft Defender for Office 365 is trusted by companies such as Ithaca College.

Hewlett-Packard Company (HP), Cushman and Wakefield, PIB Group, Swissport

Buyer's Guide

Microsoft Defender for Office 365 vs. Mimecast Advanced Email Security

August 2026

Free Report: Microsoft Defender for Office 365 vs. Mimecast Advanced Email Security

Find out what your peers are saying about Microsoft Defender for Office 365 vs. Mimecast Advanced Email Security and other solutions. Updated: August 2026.

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