KerioConnect vs Microsoft Defender for Office 365 comparison

KerioConnect vs. Microsoft Defender for Office 365

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Helped 902,894 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 (9th)

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 (8th), Secure Email Gateway (SEG) (2nd)

Mindshare comparison

As of July 2026, in the Email Archiving category, the mindshare of KerioConnect is 3.2%, up from 0.9% compared to the previous year. The mindshare of Microsoft Defender for Office 365 is 12.0%, down from 36.0% 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	12.0%
KerioConnect	3.2%
Other	84.8%

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.

Read full review

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

"This solution is our SMB alternative to Exchange, installed for more than forty SMB customers in a Linux environment with all of the collaboration features."

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

"We use the solution as a mail server. It connects with Outlook and is used for calendaring and similar tasks."

"KerioConnect has integration with 365. We can use Outlook, which has its client and can be used with Apple devices. It integrates with the App Store and Microsoft Office. It has a smart router. The spam filtering and antivirus are good."

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

"Kerio Connect is secure, flexible, and easy to control from the user interface."

"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."

"Kerio Connect is secure, flexible, and easy to control from the user interface. It has many security features able to be controlled from one place, such as anti-spam. I have found it very convenient. Additionally, you can analyze log files and share folders which is helpful."

More KerioConnect pros

"The two main features that prove most beneficial for us are URL scanning and attachment scanning."

"Microsoft Defender for Office 365 has decreased my time to detection and time to respond by one hundred percent."

"We have seen a return on investment because if we would have received a phishing email, Microsoft Defender for Office 365 would help out to detect the threat instead of crashing down the whole company."

"The risk level notifications are most valuable. We get to know what kind of intrusion or attack is there, and we can fix a problem on time."

"I would say that 90% of the spam and phishing attack emails get blocked right off the bat."

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

"The ability to respond to threats if very important."

"The DLP feature of Microsoft Defender for Office 365 is valuable, and we also use the DLP feature for email real-time detection."

More Microsoft Defender for Office 365 pros

Cons

"We are considering switching to Microsoft Exchange. One reason is that it doesn't improve our workflow and doesn't integrate well with Microsoft 365 applications."

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

"KerioConnect continues to improve with regular updates throughout the year. They must be added to the roadmap, which requires approval."

"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."

"I would like to see better support from their support team."

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

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

"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"

More KerioConnect cons

"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."

"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."

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

"I assess the stability and reliability of the solution as seven out of ten."

"If you look at other products, such as Wiz or Palo Alto's cloud, because they also have similar components in terms of how they protect cloud infrastructure or enable cloud security, Microsoft Defender for Office 365 is not up to that extent."

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

"About eight months ago, we started to measure the quantity of phishing and spam that we have been receiving, and it has been increasing a lot. That means that protection for our email is not as good as we were expecting."

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

More Microsoft Defender for Office 365 cons

Pricing and Cost Advice

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

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

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

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

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

"I know that the product is incredibly expensive."

"It's a user-base subscription."

"Compared to other brands, Microsoft Defender for Office 365's pricing is competitive."

"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."

"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."

"For large enterprise organizations, they can definitely afford it, but for small and medium organizations, they might struggle to cover the expenses."

More Microsoft Defender for Office 365 pricing and cost advice

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902,894 professionals have used our research since 2012.

Top Industries

By visitors reading reviews

Comms Service Provider

13%

Manufacturing Company

10%

Construction Company

Performing Arts

Computer Software Company

12%

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

Comparisons

Compared 18% of the time

Zimbra Collaboration vs KerioConnect

Compared 11% of the time

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Compared 9% of the time

IceWarp vs KerioConnect

Compared 9% of the time

Proofpoint Intelligent Compliance Platform vs KerioConnect

Compared 7% of the time

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Compared 6% of the time

Check Point Email Security (formerly Harmony Email & Collaboration) vs Microsoft Defender for Office 365

Compared 4% of the time

Mimecast Advanced Email Security vs Microsoft Defender for Office 365

Compared 4% of the time

Cisco Secure Email vs Microsoft Defender for Office 365

Compared 3% of the time

Barracuda Email Protection vs Microsoft Defender for Office 365

Compared 3% of the time

More Microsoft Defender for Office 365 Competitors

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