KerioConnect vs ProtonMail comparison

GFI and Proton Technologies are both solutions in the Email Applications category. GFI is ranked #9 with an average rating of 8.8, while Proton Technologies is ranked #10 with an average rating of 8.5. GFI holds a 4.0% mindshare in EA, compared to Proton Technologies’s 7.5% mindshare. Additionally, 62% of GFI users are willing to recommend the solution, compared to 66% of Proton Technologies users who would recommend it.

KerioConnect

Read 11 KerioConnect reviews

1,647 Views
1,482 Comparison Views

62% willing to recommend

ProtonMail

Read 2 ProtonMail reviews

1,418 Views
1,418 Comparison Views

66% willing to recommend

KerioConnect

ProtonMail

Comparison Buyer's Guide

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Executive Summary

We performed a comparison between KerioConnect and ProtonMail based on real PeerSpot user reviews.

Find out in this report how the two Email Applications solutions compare in terms of features, pricing, service and support, easy of deployment, and ROI.

To learn more, read our detailed KerioConnect vs. ProtonMail Report (Updated: February 2026).

Buyer's Guide

KerioConnect vs. ProtonMail

February 2026

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Helped 881,707 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 Applications

9th

Average Rating

7.2

Reviews Sentiment

7.3

Number of Reviews

Ranking in other categories

Email Archiving (6th)

ProtonMail

Ranking in Email Applications

10th

Average Rating

8.6

Reviews Sentiment

8.0

Number of Reviews

Ranking in other categories

No ranking in other categories

Mindshare comparison

As of February 2026, in the Email Applications category, the mindshare of KerioConnect is 4.0%, down from 4.9% compared to the previous year. The mindshare of ProtonMail is 7.5%, up from 3.9% compared to the previous year. It is calculated based on PeerSpot user engagement data.

Email Applications Market Share Distribution
Product	Market Share (%)
KerioConnect	4.0%
ProtonMail	7.5%
Other	88.5%

Email Applications

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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reviewer68329471

Media Content Creator Intern

Trust and anonymity play a key role in secure communications

I am uncertain about the two-factor authentication feature. I have had integrations with other Proton services and have used Proton VPN once, though it has limited features. Simple Mail, which was acquired by ProtonMail, has been very useful for me. The pricing is moderate. I have not used any paid services from ProtonMail. It is not very costly, but I have not used any premium services. I am a customer of ProtonMail. I would rate ProtonMail an eight out of ten due to their transparency and the utility of their simple login feature. My job and company name should remain hidden.

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 user interface is good."

"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."

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

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

"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."

"We have contacted technical support a handful of times and received some assistance."

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

More KerioConnect pros

"What I appreciate most about ProtonMail is that they are trusted, which is why I choose them."

"The auto encryption of attachments is valuable."

Cons

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

"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 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."

"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"

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

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

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

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

More KerioConnect cons

"I think it is good but I feel that only tech-savvy people use ProtonMail. It is not that popular among other people."

"One improvement could be the integration between ProtonMail and Proton Pass, allowing sharing of specific secrets via email."

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."

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

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

Information not available

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Top Industries

By visitors reading reviews

Comms Service Provider

13%

Computer Software Company

11%

Manufacturing Company

Performing Arts

Comms Service Provider

22%

Educational Organization

Computer Software Company

Government

Company Size

By reviewers

Large Enterprise

Midsize Enterprise

Small Business

By reviewers
Company Size	Count
Small Business	10
Midsize Enterprise	2

No data available

Questions from the Community

What do you like most about KerioConnect?

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

See all answers

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.

See all answers

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 ...

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What is your experience regarding pricing and costs for ProtonMail?

The pricing is competitive, offering good value on the average plan. It’s approximately $100 for annual billing.

See all answers

What needs improvement with ProtonMail?

In terms of what can be improved in ProtonMail, I think it is good but I feel that only tech-savvy people use ProtonMail. It is not that popular among other people. Therefore, we do not use it for ...

See all answers

What is your primary use case for ProtonMail?

My use cases include using ProtonMail for Drive occasionally for storing files. After some time, I stopped using that feature. Primarily, I use it for sending emails when I want to maintain anonymi...

See all answers

Comparisons

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Compared 38% of the time

Zimbra Collaboration vs KerioConnect

Compared 19% of the time

IceWarp vs KerioConnect

Compared 11% of the time

Microsoft Exchange Online vs KerioConnect

Compared 8% of the time

Mimecast Mailbox Continuity vs KerioConnect

Compared 4% of the time

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Google Workspace vs ProtonMail

Compared 27% of the time

Atomic Mail vs ProtonMail

Compared 19% of the time

Zoho Mail vs ProtonMail

Compared 15% of the time

Microsoft Exchange vs ProtonMail

Compared 10% of the time

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Product Reports

Buyer's Guide

KerioConnect

January 2026

Download KerioConnect product report

Buyer's Guide

Email Applications

February 2026

Download ProtonMail product report

Overview

Kerio Connect, a messaging and collaboration solution, meets the needs of small and mid-sized businesses while offering a robust feature lineup. Business users enjoy support for their favorite email client and easy web-based access. Kerio Connect is highly stable—so you can focus on business rather than unexpected downtime and recovery.

GFI

ProtonMail is the world‘s largest encrypted email provider, with over 11 million users trusting us to secure their data every day. We are the email service of choice for security-conscious enterprises.

Proton Technologies

Sample Customers

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

Wall street journal,The New york times, The Gurdian, Forbes, Fox News

Buyer's Guide

KerioConnect vs. ProtonMail

February 2026

Free Report: KerioConnect vs. ProtonMail

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We monitor all Email Applications reviews to prevent fraudulent reviews and keep review quality high. We do not post reviews by company employees or direct competitors. We validate each review for authenticity via cross-reference with LinkedIn, and personal follow-up with the reviewer when necessary.