Microsoft Defender for Office 365 vs Mimecast Mailbox Continuity comparison

Microsoft and Mimecast are both solutions in the Email Archiving category. Microsoft is ranked #1 with an average rating of 8.5, while Mimecast is ranked #7. Microsoft holds a 26.8% mindshare in EA, compared to Mimecast’s 4.8% mindshare. Additionally, 96% of Microsoft users are willing to recommend the solution, compared to 83% of Mimecast users who would recommend it.

Microsoft Defender for Offi...

Read 53 Microsoft Defender for Office 365 reviews

15,029 Views
601 Comparison Views

96% willing to recommend

Mimecast Mailbox Continuity

Read 6 Mimecast Mailbox Continuity reviews

198 Views
190 Comparison Views

83% willing to recommend

Microsoft Defender for Offi...

Mimecast Mailbox Continuity

Comparison Buyer's Guide

Download the report

Executive SummaryUpdated on Jun 29, 2025

Mimecast Mailbox Continuity and Microsoft Defender for Office 365 compete in the email security space. While Mimecast excels with robust support and pricing, Defender stands out for its comprehensive feature set.

Features: Mimecast Mailbox Continuity provides seamless email operations, strong disaster recovery, and real-time alerts for business-critical emails. Microsoft Defender for Office 365 offers advanced threat protection, sophisticated anti-phishing, and extensive integration with the Office 365 suite.

Room for Improvement: Mimecast could enhance integration with other platforms, expand anti-phishing measures, and diversify threat detection capabilities. Microsoft Defender could streamline initial setup, improve customer support, and offer more customizable options for users.

Ease of Deployment and Customer Service: Mimecast is praised for its straightforward deployment and responsive customer service. Microsoft Defender, though more complex in initial setup, benefits from deep integration with Microsoft products, facilitating easier management for existing users.

Pricing and ROI: Mimecast Mailbox Continuity offers competitive setup costs and solid ROI by minimizing outage risks. Microsoft's Defender for Office 365, despite higher upfront costs, delivers significant value through enhanced security features, justifying the investment with higher ROI for robust security needs.

To learn more, read our detailed Microsoft Defender for Office 365 vs. Mimecast Mailbox Continuity Report (Updated: September 2025).

Buyer's Guide

Microsoft Defender for Office 365 vs. Mimecast Mailbox Continuity

September 2025

Download the complete report

Helped 868,787 peers since 2012

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

Microsoft Defender for Offi...

Ranking in Email Archiving

1st

Average Rating

8.4

Reviews Sentiment

6.9

Number of Reviews

Ranking in other categories

Email Security (1st), Advanced Threat Protection (ATP) (2nd), Microsoft Security Suite (10th), Secure Email Gateway (SEG) (1st)

Mimecast Mailbox Continuity

Ranking in Email Archiving

7th

Average Rating

8.0

Reviews Sentiment

6.1

Number of Reviews

Ranking in other categories

No ranking in other categories

Mindshare comparison

As of October 2025, in the Email Archiving category, the mindshare of Microsoft Defender for Office 365 is 26.8%, up from 18.4% compared to the previous year. The mindshare of Mimecast Mailbox Continuity is 4.8%, down from 5.5% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Email Archiving Market Share Distribution
Product	Market Share (%)
Microsoft Defender for Office 365	26.8%
Mimecast Mailbox Continuity	4.8%
Other	68.4%

Email Archiving

Featured Reviews

Tolu Omolaja

Head of Department of Network Communications at Eko electricity

Great URL scanning and attachment scanning, but I would like more proactive threat analysis

The two main features that prove most beneficial for us are URL scanning and attachment scanning. URL scanning involves an automatic scan of links and emails. When a user clicks on a link within an email, the system promptly checks the link's safety. If the link is deemed safe, access is granted automatically. However, if it is flagged as unsafe, we receive feedback and notification to caution us about the potentially harmful link. At this point, we are presented with the option to proceed or return. I have personally witnessed the system identify a few unsafe links, making this the primary advantage of using the solution. The second crucial aspect is the scanning of attachments. When an email containing an attachment arrives, we receive a notification of the new email, along with information that the attachment is being scanned for threats. This additional layer of security provides peace of mind for our organization. While Microsoft Defender for Office 365 offers numerous features, these two stand out as particularly impressive and valuable to us.

Read full review

Todd Blake

Senior IT Specialist at COMMUNITY HEALTH CONNECTIONS INC

Provides peace of mind and expands well but needs a better interface

It's a hosted solution. I'm not sure which version of the solution Im on at this time. I would advise others to research all the options out there and see what the best fit is. We started this mailbox continuity project before we moved to Office 365. And now that we've moved to Office 365, we kind of don't need this piece of technology in the same way that we used to need it when we had an on-prem exchange. Therefore, make sure that you actually need it and then research to find the best options. Overall, I would rate the solution seven out of ten.

Read full review

Quotes from Members

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

Pros

"The initial setup is straightforward. You just add the license, click it, and then you can set up the rules. It is quite simple."

"The solution is very easy to use. All you have to do is to assign the license to the end-user and it's done. The customer will only have the feature activated, and the solution will monitor the emails to determine if they are a threat or not."

"The deployment capability is a great feature."

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

"It gives us visibility into threats and, for endpoints, it helps us to prioritize threats. We used to have a lack of visibility, but now our time to detect and respond has decreased."

"Microsoft Defender for Office 365's most valuable feature is its performance."

"The stability of Microsoft Defender for Office 365 is fantastic."

"My experience with customer support and technical support for Microsoft Defender for Office 365 has been excellent."

More Microsoft Defender for Office 365 pros

"The most valuable feature of Mimecast Mailbox Continuity is real-time alerts."

"It has all the features required for distribution, such as the ability to mail."

"Mimecast has some good support services in place."

"The security is pretty good, and that's why we're going to upgrade to an even more advanced package. We used it when we had a power issue, and it works. It has been pretty reliable, and the support has been quite good."

"The Large File Send feature comes in handy when you have to send fairly large attachments."

"We're now certain business-critical mail is perfectly protected in multiple ways."

Cons

"One area for improvement is support, in terms of being able to reach them and, especially, technical support for configuration."

"In some situations, it has not been able to pick impersonated emails having no attachments. Technical support definitely has a scope for improvement."

"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."

"We still see many false positives from time to time with Microsoft Defender for Office 365, so it would be good if we can reduce those false positives and provide better workflows for our end users, as sometimes they may not know what to do when they encounter a false positive."

"Microsoft should provide more documentation for users so they can self-educate. I would like to see more documentation for advanced security features."

"Configuration requires going to a lot of places rather than just accessing one tab."

"Too many false positives and lacks an accurate capability to detect malicious SharePoint sites."

"Microsoft Defender for Office 365 should improve the troubleshooting tools. It's unclear whether the device is blocked at the firewall level or at the device itself. The granularity needed for troubleshooting is currently lacking. From my perspective, Microsoft should address this issue to benefit many users who likely share the same sentiment."

More Microsoft Defender for Office 365 cons

"The solution is expensive in comparison to similar solutions."

"The interface isn't the best. How everything works on the back end is confusing."

"Technical support has been slower than it was in the past, likely due to the pandemic."

"The interface and the documentation could be improved. They can also include some more training resources and content like video. While setting things up, I had to search for the information quite a bit. It took me time to find the correct way to do something. The information is there, but it is sort of all over the place. They can create a better help knowledge base or help portal. It retains your email for 45 days. They can maybe increase this duration."

"The price of the solution is expensive. It can improve by reducing the price."

Pricing and Cost Advice

"Microsoft Defender for Office 365 is an add-on to the Office license. Many customers are purchasing this solution."

"The pricing has become expensive."

"It's a user-base subscription."

"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 is much more expensive than using another solution because we have had to include some options and upgrade our license."

"Defender is a little bit more expensive as compared to others. We are in the manufacturing environment. So, we don't have a high budget for all of our endpoint devices. Its cost is a major concern for us."

"From the pricing point of view, like any other product in the market, there is scope for negotiation."

"The solution could be better by simplifying the business model of their licensing. It was hard to figure out how to get the licensing done for the environment, initially."

More Microsoft Defender for Office 365 pricing and cost advice

"The price of Mimecast Mailbox Continuity is expensive."

"Its price is in the middle range. It is a structured licensing model where there are various components that you can add or choose to add or not."

See which vendors are best for you

Use our free recommendation engine to learn which Email Archiving solutions are best for your needs.

See recommendations

868,787 professionals have used our research since 2012.

Top Industries

By visitors reading reviews

Computer Software Company

15%

Financial Services Firm

Manufacturing Company

Comms Service Provider

No data available

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	23
Midsize Enterprise	8
Large Enterprise	27

No data available

Questions from the Community

What do you like most about Microsoft Defender for Office 365?

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 indi...

See all answers

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

Microsoft is quite affordable with a lot of features available for any size organization.

See all answers

What needs improvement with Microsoft Defender for Office 365?

I think that Microsoft Defender for Office 365 could be improved if it could use VirusTotal to compare the programs or anything that I download. VirusTotal helps to identify viruses, malware, troja...

See all answers

Ask a question

Earn 20 points

Comparisons

Proofpoint Email Protection vs Microsoft Defender for Office 365

Compared 12% of the time

Mimecast Email Security vs Microsoft Defender for Office 365

Compared 7% of the time

Barracuda Email Protection vs Microsoft Defender for Office 365

Compared 6% of the time

Check Point Harmony Email & Collaboration vs Microsoft Defender for Office 365

Compared 6% of the time

Microsoft Defender for Business vs Microsoft Defender for Office 365

Compared 5% of the time

More Microsoft Defender for Office 365 Competitors

No data available

Product Reports

Buyer's Guide

Microsoft Defender for Office 365

September 2025

Microsoft Defender for Office 365 report

Download Microsoft Defender for Office 365 product report

Buyer's Guide

Email Archiving

October 2025

Download Mimecast Mailbox Continuity product report

Also Known As

MS Defender for Office 365

No data available

Overview

Microsoft Defender for Office 365 is a comprehensive security solution designed to protect organizations against advanced threats in their email, collaboration, and productivity environments. It combines the power of Microsoft's threat intelligence, machine learning, and behavioral analytics to provide real-time protection against phishing, malware, ransomware, and other malicious attacks.

With Microsoft Defender for Office 365, organizations can safeguard their email communication by detecting and blocking malicious links, attachments, and unsafe email content. It employs advanced anti-phishing capabilities to identify and prevent sophisticated phishing attacks that attempt to steal sensitive information or compromise user credentials.

This solution also offers robust protection against malware and ransomware. It leverages machine learning algorithms to analyze email attachments and URLs in real-time, identifying and blocking malicious content before it reaches users' inboxes. Additionally, it provides advanced threat-hunting capabilities, allowing security teams to proactively investigate and respond to potential threats.

Microsoft Defender for Office 365 goes beyond email protection and extends its security features to other collaboration tools like SharePoint, OneDrive, and Teams. It scans files and documents stored in these platforms, ensuring that they are free from malware and other malicious content. It also provides visibility into user activities, helping organizations detect and mitigate insider threats.

Furthermore, this solution offers rich reporting and analytics capabilities, providing organizations with insights into their security posture and threat landscape. It enables security administrators to monitor and manage security incidents, track trends, and take proactive measures to enhance their overall security posture.

Microsoft

Mimecast Mailbox Continuity provides uninterrupted access to live and archive email using Outlook for Windows, the web and mobile applications.

Mimecast

Sample Customers

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

DAC Beachcroft, OceanFirst, Currie & Brown, Alexander Forbes, Lagan Group, Lals Group, Greater Manchester Fire and Rescue Service, Wedlake Bell, Macmillan Cancer Support, Bech-Bruun

Buyer's Guide

Microsoft Defender for Office 365 vs. Mimecast Mailbox Continuity

September 2025

Free Report: Microsoft Defender for Office 365 vs. Mimecast Mailbox Continuity

Find out what your peers are saying about Microsoft Defender for Office 365 vs. Mimecast Mailbox Continuity and other solutions. Updated: September 2025.

DOWNLOAD NOW

868,787 professionals have used our research since 2012.

See our Microsoft Defender for Office 365 vs. Mimecast Mailbox Continuity report.

See our list of best Email Archiving vendors.

We monitor all Email Archiving reviews to prevent fraudulent reviews and keep review quality high. We do not post reviews by company employees or direct competitors. We validate each review for authenticity via cross-reference with LinkedIn, and personal follow-up with the reviewer when necessary.