No more typing reviews! Try our Samantha, our new voice AI agent.

Heimdal Email Security vs Microsoft Defender for Office 365 comparison

Sponsored
 

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) (15th), Data Loss Prevention (DLP) (21st), Cloud Access Security Brokers (CASB) (11th), Distributed Denial-of-Service (DDoS) Protection (7th), Software Defined WAN (SD-WAN) Solutions (13th), Access Management (12th), Bot Management (3rd), ZTNA as a Service (8th), ZTNA (3rd), Secure Access Service Edge (SASE) (10th), Remote Browser Isolation (RBI) (3rd)
Heimdal Email Security
Ranking in Email Security
61st
Average Rating
9.0
Reviews Sentiment
7.9
Number of Reviews
1
Ranking in other categories
Fraud Detection and Prevention (60th)
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 (9th), Secure Email Gateway (SEG) (1st)
 

Mindshare comparison

As of April 2026, in the Email Security category, the mindshare of Cloudflare One is 1.5%, down from 1.8% compared to the previous year. The mindshare of Heimdal Email Security is 0.3%, up from 0.2% compared to the previous year. The mindshare of Microsoft Defender for Office 365 is 8.8%, down from 13.5% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Email Security Mindshare Distribution
ProductMindshare (%)
Microsoft Defender for Office 3658.8%
Cloudflare One1.5%
Heimdal Email Security0.3%
Other89.4%
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

"The best feature is rate limiting. If I'm expecting 500 visits per hour, Cloudflare will limit the requests if I suddenly get 50,000."
"Cloudflare Zero Trust Platform removes the risk of exposing the applications to the public."
"Cloudflare DDoS mitigates DDoS attacks."
"Cloudflare is simple to use."
"Cloudflare DDoS is better than its competitors for its security, deployment, and scalability."
"Cloudflare is simple to use."
"The capabilities of the software are strong enough for me to do what it's supposed to do. For me, we don't need to do a lot of configuration on our site. We just enable it and monitor it."
"I'm very satisfied with the environment and the dashboard."
"It is stable and reliable."
"Overall, I would rate Microsoft Defender for Office 365 at a ten."
"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."
"We use Microsoft Defender for its ability to integrate with existing business technologies, which is beneficial for protecting business areas."
"Microsoft Defender for Office 365 facilitates efficient management and updates through the cloud. We do not have to worry about incompatibilities. It just works."
"The good part is that you don't have to configure it, which is very convenient."
"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."
"One of the best features of the tool is its capability to aggregate insights from different workloads, basically from the Office 365 and endpoints part."
"Since we have started using the solution, there have been fewer compromises."
 

Cons

"There are premium tier live service and lower tier live service, so we opted for the lower tier. But there is no medium tier where we pay a little extra and get a bit more service. So if that can be improved."
"The initial onboarding was causing us some confusion."
"Our customers no longer use Cloudflare because its service is subpar."
"For the topic of improvement, providing some training material is one of my suggestions."
"From a logging perspective, it is still a bit difficult to see exactly what users are being blocked with the current views."
"Our customers no longer use Cloudflare because its service is subpar."
"The initial onboarding was causing us some confusion."
"The tool should provide on-premise versions. Currently, all versions are cloud-based."
"The solution could be less expensive."
"The visibility into threats is not up to the mark, as I do not have control. I rate my experience with Microsoft Defender for Office 365 as six out of ten due to troubleshooting and pricing concerns."
"Microsoft Defender for Office 365's Mac functionality requires improvement to deliver the same level of protection found on Windows devices."
"From a development point of view, if I wanted to do development on my actual machine where Defender is, the organization can set certain policies or Defender makes that prohibitive."
"We need a separate license and we don't know how to get the license that is required."
"Configuration requires going to a lot of places rather than just accessing one tab."
"The inbuilt analysis of false positives can be faster. It's not slow, but it can be faster."
"The cost of Security Copilot is up there right now, and I think it needs to come down for more people to adopt."
"Too many false positives and lacks an accurate capability to detect malicious SharePoint sites."
 

Pricing and Cost Advice

"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 solution's pricing lacks transparency."
"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."
"The solution is not that expensive."
"The pricing is somewhere in the middle. I would rate the pricing a seven out of ten."
"The price tag is no longer $200,000, but rather $300,000 to $400,000. It's twice."
Information not available
"The product is expensive."
"Microsoft Defender for Office 365 comes with Microsoft Windows. It is free with the operating system."
"While Microsoft Defender for Office 365 necessitates pricier E3 or E5 subscriptions, the extensive functionality offered by these licenses across various Microsoft products justifies the investment."
"The pricing is normal. Considering its popularity, it's not overpriced."
"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."
"The product is very expensive."
"The pricing has become expensive."
report
Use our free recommendation engine to learn which Email Security solutions are best for your needs.
885,789 professionals have used our research since 2012.
 

Top Industries

By visitors reading reviews
Construction Company
23%
Comms Service Provider
10%
Financial Services Firm
7%
Computer Software Company
6%
Construction Company
20%
Comms Service Provider
7%
Logistics Company
7%
Energy/Utilities Company
7%
Computer Software Company
13%
Financial Services Firm
8%
Manufacturing Company
8%
Comms Service Provider
6%
 

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 Business24
Midsize Enterprise10
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, ...
Ask a question
Earn 20 points
What needs improvement with Microsoft Defender for Office 365?
The inbuilt analysis of false positives can be faster. It's not slow, but it can be faster.
What is your primary use case for Microsoft Defender for Office 365?
My use case for Microsoft Defender for Office 365 is for email protection, safe links, protection of links, documents...
 

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: February 2026.
885,789 professionals have used our research since 2012.