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Heimdal Email Security vs Microsoft Defender for Office 365 comparison

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Comparison Buyer's Guide

Executive Summary

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
Sponsored
Ranking in Email Security
20th
Average Rating
8.6
Reviews Sentiment
6.5
Number of Reviews
23
Ranking in other categories
Secure Web Gateways (SWG) (13th), Data Loss Prevention (DLP) (20th), Cloud Access Security Brokers (CASB) (12th), Distributed Denial-of-Service (DDoS) Protection (7th), Software Defined WAN (SD-WAN) Solutions (12th), Access Management (11th), Bot Management (3rd), ZTNA as a Service (9th), ZTNA (4th), Secure Access Service Edge (SASE) (10th), Remote Browser Isolation (RBI) (3rd)
Heimdal Email Security
Ranking in Email Security
59th
Average Rating
9.0
Reviews Sentiment
7.9
Number of Reviews
1
Ranking in other categories
Fraud Detection and Prevention (56th)
Microsoft Defender for Offi...
Ranking in Email Security
2nd
Average Rating
8.4
Reviews Sentiment
6.8
Number of Reviews
61
Ranking in other categories
Email Archiving (1st), Advanced Threat Protection (ATP) (2nd), Microsoft Security Suite (8th), Secure Email Gateway (SEG) (1st)
 

Mindshare comparison

As of May 2026, in the Email Security category, the mindshare of Cloudflare One is 1.7%, up from 1.6% compared to the previous year. The mindshare of Heimdal Email Security is 0.4%, up from 0.2% compared to the previous year. The mindshare of Microsoft Defender for Office 365 is 6.9%, down from 12.9% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Email Security Mindshare Distribution
ProductMindshare (%)
Microsoft Defender for Office 3656.9%
Cloudflare One1.7%
Heimdal Email Security0.4%
Other91.0%
Email Security
 

Featured Reviews

CV
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.
Melvin Ong - PeerSpot reviewer
Country Manager at PT Symcaw Solutions Indonesia
Straightforward to set up, reliable, and offers good functionality
We primarily use the solution for email security and general email management.  It's improved our productivity.  The solution works well overall. The functionality is very good.  The setup process is easy.  It is stable and reliable. It's scalable.  I don't have any specific areas that need…
Emeka Ndulu - PeerSpot reviewer
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.

Quotes from Members

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

Pros

"Cloudflare is simple to use."
"Clover is the best product globally."
"Enables me to work from two locations."
"Cloudflare, in my opinion, was easy to implement."
"This solution is easy to understand and easy to configure."
"Cloudflare DDoS is better than its competitors for its security, deployment, and scalability."
"The simplicity of the solution is its valuable features as almost no effort was needed to learn the configurations. It is also one of the cheapest firewalls available in this category."
"I'm very satisfied with the environment and the dashboard."
"It is stable and reliable."
"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."
"It also gives me good visibility because, with Defender, I'm using a Microsoft product to defend Microsoft products. The integration was really seamless and I have wide visibility because it picks up almost everything. Literally, I can see almost every activity that happens, from the e-mail to the workstation itself."
"Microsoft Defender for Office 365 is a stable solution."
"The coolest feature of Microsoft Defender for Office 365 is its ability to look for phishing emails."
"Microsoft Defender for Office 365 is a cloud-based email filtering service that helps protect our organization against unknown malware and viruses by providing robust zero-day protection and includes features to safeguard our organization from harmful links in real-time."
"The insights provided with Microsoft Defender for Office 365 are helpful because it comes with the E5 license, and by default, we can use a lot of capabilities."
"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."
"The most valuable feature of Microsoft Defender for Office 365 is the ease of use."
 

Cons

"The response time for support must be reduced."
"Our customers no longer use Cloudflare because its service is subpar."
"Cloudflare One is not very powerful, but for what we require, it is basic and sufficient."
"They don't have a person to provide support for customers using the solution under their free plan."
"The tool should provide on-premise versions. Currently, all versions are cloud-based."
"From a logging perspective, it is still a bit difficult to see exactly what users are being blocked with the current views."
"Cloudflare Zero Trust Platform needs to improve its documentation. It took time to do the implementation."
"The pricing is an area that can be improved. Pricing, as far as I recall, was the source of our problems."
"The solution could be less expensive."
"In one of the reports I can get the exact place where a vulnerable file resides. But for that, I need to explicitly go into the device and check. If they could include that file part in the report, without my having to go to the device itself, that would help."
"Specifically, within Microsoft Defender for Office 365, I want it to improve the DLP capabilities."
"The cost of Security Copilot is up there right now, and I think it needs to come down for more people to adopt."
"The GUI is sometimes slow to fetch the device report and could be improved."
"In some situations, it has not been able to pick impersonated emails having no attachments. Technical support definitely has a scope for improvement."
"I'd like some additional features any product can give me to protect our environment in a better way."
"Microsoft should provide more documentation for users so they can self-educate. I would like to see more documentation for advanced security features."
"It would be better if it were more scalable. It depends on the architecture, but we would like to make it more scalable for both data centers."
 

Pricing and Cost Advice

"The solution's pricing lacks transparency."
"The pricing is somewhere in the middle. I would rate the pricing a seven out of ten."
"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."
"Cloudflare Zero Trust Platform's pricing is good."
"The price tag is no longer $200,000, but rather $300,000 to $400,000. It's twice."
"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."
"The solution is not that expensive."
Information not available
"From the pricing point of view, like any other product in the market, there is scope for negotiation."
"For large enterprise organizations, they can definitely afford it, but for small and medium organizations, they might struggle to cover the expenses."
"I was working in the government and it was too expensive for us to use our Microsoft products."
"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."
"The license is expensive because the cost is based on the number of users."
"Defender for 365 comes in various plans and licenses, along with other Microsoft security solutions. Purchasing this kind of package or security bundle gives good value for money, and that's what I recommend."
"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."
"It is much more expensive than using another solution because we have had to include some options and upgrade our license."
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Top Industries

By visitors reading reviews
Construction Company
20%
Comms Service Provider
10%
Financial Services Firm
8%
Manufacturing Company
6%
Construction Company
20%
Comms Service Provider
7%
Logistics Company
7%
Energy/Utilities Company
7%
Computer Software Company
12%
Financial Services Firm
9%
Manufacturing Company
8%
Comms Service Provider
7%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
By reviewers
Company SizeCount
Small Business10
Midsize Enterprise2
Large Enterprise11
No data available
By reviewers
Company SizeCount
Small Business25
Midsize Enterprise12
Large Enterprise31
 

Questions from the Community

What needs improvement with Cloudflare Access?
Cloudflare Access has strong integration with Microsoft, among other platforms. However, when it comes to Kaspersky, ...
What is your primary use case for Cloudflare Access?
Cloudflare Access provides secure access to internal applications for employees, external members of the organization...
What advice do you have for others considering Cloudflare Access?
Cloudflare Access is one of the best integrations available. While about two hundred vendors offer similar services, ...
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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...
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 ...
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.
 

Also Known As

Cloudflare Area 1 Email Security, Cloudflare Bot Management, Cloudflare Gateway, Cloudflare Zero Trust Platform, Cloudflare DDoS, Cloudflare SASE & SSE Platform
MailSentry
MS Defender for Office 365
 

Overview

 

Sample Customers

23andMe
Brother, Symbion, CPH West
Microsoft Defender for Office 365 is trusted by companies such as Ithaca College.
Find out what your peers are saying about Proofpoint, Microsoft, Check Point Software Technologies and others in Email Security. Updated: April 2026.
893,221 professionals have used our research since 2012.