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Fortra's Clearswift Secure Email Gateway vs Microsoft Defender for Office 365 comparison

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Comparison Buyer's Guide

Executive SummaryUpdated on Nov 8, 2026

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

Fortra's Clearswift Secure ...
Ranking in Email Security
31st
Average Rating
8.6
Reviews Sentiment
7.1
Number of Reviews
0
Ranking in other categories
No ranking in other categories
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 (2nd), Advanced Threat Protection (ATP) (3rd), Microsoft Security Suite (8th), Secure Email Gateway (SEG) (2nd)
 

Mindshare comparison

As of November 2026, in the Email Security category, the mindshare of Fortra's Clearswift Secure Email Gateway is 1.4%, up from 1.0% compared to the previous year. The mindshare of Microsoft Defender for Office 365 is 5.0%, down from 10.6% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Email Security Mindshare Distribution
ProductMindshare (%)
Microsoft Defender for Office 3655.0%
Fortra's Clearswift Secure Email Gateway1.4%
Other93.6%
Email Security
 

Featured Reviews

PC
Systems Administrator at a financial services firm with 1,001-5,000 employees
Stable, but malware needs improvement and customer support is poor
They need to improve the malware in the product. I am not satisfied with Clearswift because of the lack of customer support. The support is poor, the supplier takes a lot of time and it's expensive. We have some issues here when I contact the supplier, it takes a lot of time for them to get back to us but there's no solution. I am now looking at Symantec as a possible alternative.
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

"Ability to create your own content-filtering policies with relative ease."
"Go for it! I think it's an excellent product with great technical support."
"We use a few features for web proxy, and another feature is the email content filter and malware for our internal policy in the email content."
"A stable solution."
"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."
"Microsoft Defender for Office 365 has improved my organization's security. It makes it easier to manage the infrastructure without the help of third-party applications."
"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."
"The feature I like the most about Microsoft Defender for Office 365 is that it typically runs in the background—you do not know it is there until you need to access it."
"The initial setup was easy."
"We use Microsoft Defender for its ability to integrate with existing business technologies, which is beneficial for protecting business areas."
"The most valuable feature of Microsoft Defender for Office 365 is data backups that we can provide through ticket requests."
"The email protection is excellent, especially in terms of anti-phishing policies."
 

Cons

"Malware needs improvement."
"I am not satisfied with Clearswift because of the lack of customer support."
"FTP server and TRUST Manager functionality."
"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."
"I assess the stability and reliability of the solution as seven out of ten."
"Microsoft needs to broaden its global support presence by establishing teams of subject-matter experts in all regions."
"Specifically, within Microsoft Defender for Office 365, I want it to improve the DLP capabilities."
"Configuration at the mid-level could be improved for the support team."
"We are waiting for better software to block viruses."
"We need to be able to whitelist data at the backend."
"I think Microsoft Defender for Office 365 can be improved by creating more educational pieces about not just looking for malware."
 

Pricing and Cost Advice

Information not available
"From the pricing point of view, like any other product in the market, there is scope for negotiation."
"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."
"Microsoft Defender is expensive. I typically recommend it only if clients have the budget. Otherwise, I would suggest an alternative."
"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."
"Microsoft Defender for Office 365 is an add-on to the Office license. Many customers are purchasing this solution."
"I know that the product is incredibly expensive."
"The pricing is normal. Considering its popularity, it's not overpriced."
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Top Industries

By visitors reading reviews
Construction Company
12%
Retailer
11%
Financial Services Firm
11%
Comms Service Provider
9%
Computer Software Company
11%
Manufacturing Company
10%
Financial Services Firm
8%
Comms Service Provider
7%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
No data available
By reviewers
Company SizeCount
Small Business24
Midsize Enterprise11
Large Enterprise32
 

Questions from the Community

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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 a standalone product. It's very competitive compared to what competitors are ch...
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 for malware. We are seeing a lot more malware-less emails that Defender for Offi...
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

No data available
MS Defender for Office 365
 

Overview

 

Sample Customers

Information Not Available
Microsoft Defender for Office 365 is trusted by companies such as Ithaca College.
Find out what your peers are saying about Fortra's Clearswift Secure Email Gateway vs. Microsoft Defender for Office 365 and other solutions. Updated: November 2026.
920,939 professionals have used our research since 2012.