KerioConnect vs Microsoft Defender for Office 365 comparison

KerioConnect vs. Microsoft Defender for Office 365

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Helped 909,725 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

KerioConnect

Ranking in Email Archiving

7th

Average Rating

7.2

Reviews Sentiment

7.3

Number of Reviews

Ranking in other categories

Email Applications (8th)

Microsoft Defender for Offi...

Ranking in Email Archiving

1st

Average Rating

8.4

Reviews Sentiment

6.8

Number of Reviews

Ranking in other categories

Email Security (2nd), Advanced Threat Protection (ATP) (3rd), Microsoft Security Suite (9th), Secure Email Gateway (SEG) (2nd)

Mindshare comparison

As of August 2026, in the Email Archiving category, the mindshare of KerioConnect is 3.3%, up from 0.9% compared to the previous year. The mindshare of Microsoft Defender for Office 365 is 10.7%, down from 35.9% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Email Archiving Mindshare Distribution
Product	Mindshare (%)
Microsoft Defender for Office 365	10.7%
KerioConnect	3.3%
Other	86.0%

Email Archiving

Featured Reviews

Marcelino Mongcal

Senior Systems Tech/Admin at Samco Software Inc.

A seamless setup ensures smooth communication with comprehensive support

We remain a partner with Sophos and use XG S Firewalls without AWS implementation. We only use Sophos endpoint and Sophos Central. We host some clients on-premise while others we host remotely. The VPN connection is easy and proprietary, so it's not open to any other VPN clients. Communication with other mail servers is seamless. It can communicate with Gmail and Outlook without issues, provided the DNS settings are correct. We monitor our servers and security logs, implementing GeoIP blocking. We frequently block China and India IPs due to brute force attacks on our servers. We have extensive experience with KerioConnect. Backing up and maintaining it is straightforward compared to Microsoft Exchange, making it administrator-friendly. On a scale of 1-10, this solution rates an 8.

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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.

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 solution is easy to maintain, unlike Exchange. It's easy to create multiple domains and back up and restore if needed. It also has good security features like anti-spam and antivirus."

"What I like most about Kerio Connect is that it supports ActiveSync, and that is its most critical feature. The solution is also a nice, simple, robust, and stable mail server."

"The user interface is good."

"Backing up and maintaining it is straightforward compared to Microsoft Exchange, making it administrator-friendly."

"It's relatively simple to use."

"The most valuable features are its ease of use, excellent pricing, and it is platform agnostic."

"As long as the operating is stable, the Kerio connect will be very stable as well, so we don't have any problem with it."

"The most valuable features are security and privacy because you installed it on your server, within your company premises, not in the cloud."

More KerioConnect pros

"The product is not resource-intensive."

"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."

"I like its investigation capabilities, as that is what is most important to me. It is fairly simple with a user-friendly interface."

"Microsoft Defender for Office 365's most valuable features are safe attachments and safe links."

"The most valuable feature of Microsoft Defender for Office 365 is data backups that we can provide through ticket requests."

"The technical support is good and quick to resolve issues."

"With Defender for Office 365, we have been able to increase the security posture across our organization."

"It also gives the vulnerability status according to the versions you have selected. Let's say you have Google Chrome. It mentions the versions it has, and it updates. Within two hours of an update, it is reflected in the dashboard. That's really nice to have."

More Microsoft Defender for Office 365 pros

Cons

"Most of our clients use Outlook and Kerio Connect. Occasionally, Kerio can be a bit slow. They could make it faster to get onto the web interface without so much load time. It's just slow with Outlook, however, for some reason."

"We cannot compete with them because they're fully integrated with their applications."

"I don't particularly like this solution. I would not recommend this solution to others."

"The solution could improve the redundancy because we only have one copy of the Kerio Connect server on our hardware. The next step for us is to move to the cloud and if Kerio does not have a cloud version available they should release one"

"It could be simpler to use and install, but I still wouldn't use it because there isn't a compelling use case."

"KerioConnect is stable as long as you use a strong password."

"The search and archiving documentation capabilities need to be stronger."

"Having a native Outlook map integration would make Kerio Connect better."

More KerioConnect cons

"The only thing they should improve is the licensing model. They should stop changing it. A year ago, the five features I mentioned were included in one product. Now, three of them are bundled into one product, and you have to pay extra for the other two. I don't mind paying extra, but I don't want them to change it every year or every six months. I need to know what I'm looking at and not worry about it next year."

"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."

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

"We are waiting for better software to block viruses."

"Microsoft Defender for Office 365 could improve by giving customers information on techniques to prevent threats."

"The XDR dashboard has room for improvement."

"We need to be able to whitelist data at the backend."

More Microsoft Defender for Office 365 cons

Pricing and Cost Advice

"The solution's pricing depends on how long you plan to keep it because you pay on a per-year basis. You might have a one-time setup cost for something like Microsoft Exchange or a Linux mail server. I'd say this solution is expensive on a per-year basis, almost 2000-3000 dollars annually. It doesn't seem to pay off yet, so we're considering switching to another product."

"The price of Kerio Connect is better when comparing it to others solutions."

"KerioConnect has a first-time cost and yearly subscription. It is not expensive."

"The pricing is about $3 per mailbox per month."

"The license is expensive because the cost is based on the number of users."

"I know that the product is incredibly expensive."

"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."

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

"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."

"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."

"Microsoft Defender is expensive. I typically recommend it only if clients have the budget. Otherwise, I would suggest an alternative."

More Microsoft Defender for Office 365 pricing and cost advice

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Top Industries

By visitors reading reviews

Comms Service Provider

14%

Manufacturing Company

11%

Construction Company

Retailer

Computer Software Company

11%

Manufacturing Company

Financial Services Firm

Comms Service Provider

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	10
Midsize Enterprise	2

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

Questions from the Community

What is your experience regarding pricing and costs for KerioConnect?

The pricing is very easy to understand. As a partner, we have a monitoring system that informs us when subscriptions expire, allowing us to handle renewals. The pricing is very competitive.

What needs improvement with KerioConnect?

Since KerioConnect is a setup and go solution, everything works on its own. The only administrative tasks required are keeping it up to date, monitoring security logs, and ensuring protection from ...

What is your primary use case for KerioConnect?

Small medium-sized businesses are our primary focus, particularly in warehouse distribution and retail sectors. We are a reseller and purchase directly from Sophos.

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.

Microsoft Exchange vs KerioConnect

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Product Reports

KerioConnect

Download KerioConnect product report

Microsoft Defender for Office 365

Download Microsoft Defender for Office 365 product report

Microsoft Defender for Office 365 report

Also Known As

No data available

MS Defender for Office 365

Overview

KerioConnect delivers easy-to-use and secure email, calendar, and collaboration tools compatible with Office, Apple, and ActiveSync. Cost-effective and flexible, it suits on-premise installations, especially for SMBs seeking privacy and security.

KerioConnect offers a comprehensive email server experience with minimal resource needs and effective spam filtering. Compatible across platforms, it supports Outlook, enabling organizations to manage corporate communications efficiently. Its ability to host multiple domains makes it suitable for sectors like warehouse distribution and retail, with installation options that enhance security and privacy. However, faster Outlook integration, improved MS Teams and CRM system integration, and AI functionalities are sought after by users. Some demand a cloud version, Linux support, and better documentation. Still, KerioConnect remains a reliable choice for those needing on-premise capabilities.

What are KerioConnect's Key Features?

Ease of Use: Simplified interface for seamless navigation.
Robust Security: Advanced protection measures to safeguard data.
Spam Filtering: Efficiently reduces unwanted emails.
Platform Compatibility: Integrates with Office, Apple, and ActiveSync.
Log Analysis: Offers detailed insights for server management.
Multiple Domain Support: Manages diverse domains with ease.

What Benefits Should Users Expect?

Cost Efficiency: Lowers operational costs compared to alternatives.
Resource Minimization: Requires minimal system resources.
Deployment Flexibility: Allows tailored on-premise installations.
Enhanced Security: Provides privacy through internal hosting options.
Reliable Support: Access to reseller services from Sophos.

KerioConnect is widely utilized in SMBs across sectors like retail and warehouse distribution for its capability to handle multiple domains and integrate with Outlook for communication management. Resellers offer it as a dependable on-site email management solution, letting businesses maintain oversight and security control.

GFI

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

Sample Customers

Southern Tier Brewing Company, Innotta, Baustoff + Metall, Hamifleurs, Chanson TV, Ryman Stationery

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

KerioConnect vs. Microsoft Defender for Office 365