Try our new research platform with insights from 80,000+ expert users

KerioConnect vs ProtonMail comparison

GFI and Proton Technologies are both solutions in the Email Applications category. GFI is ranked #10 with an average rating of 7.5, while Proton Technologies is ranked #9 with an average rating of 8.5. GFI holds a 4.5% mindshare in EA, compared to Proton Technologies’s 6.4% mindshare. Additionally, 57% of GFI users are willing to recommend the solution, compared to 66% of Proton Technologies users who would recommend it.
KerioConnect
Read 10 KerioConnect reviews
  • 1,754 Views
  • 1,701 Comparison Views
57% willing to recommend
ProtonMail
Read 2 ProtonMail reviews
  • 1,200 Views
  • 1,200 Comparison Views
66% willing to recommend
 

Comparison Buyer's Guide

Download the report
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.

DOWNLOAD THE COMPLETE REPORT
To learn more, read our detailed KerioConnect vs. ProtonMail Report (Updated: July 2025).
Buyer's Guide
KerioConnect vs. ProtonMail
July 2025
Download the complete report
Helped 865,384 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
10th
Average Rating
6.8
Reviews Sentiment
7.1
Number of Reviews
10
Ranking in other categories
Email Archiving (8th)
ProtonMail
Ranking in Email Applications
9th
Average Rating
8.6
Reviews Sentiment
8.0
Number of Reviews
2
Ranking in other categories
No ranking in other categories
 

Mindshare comparison

As of August 2025, in the Email Applications category, the mindshare of KerioConnect is 4.5%, up from 4.1% compared to the previous year. The mindshare of ProtonMail is 6.4%, up from 3.6% compared to the previous year. It is calculated based on PeerSpot user engagement data.
Email Applications
 

Featured Reviews

David Bloomer - PeerSpot reviewer
Lightweight, simple, and robust; easy to maintain and doesn't require a lot of system resources to run
Kerio Connect does as advertised, so there are no real issues with the product itself. It's developed regularly, so there are constant updates. Possibly, the support and development have lessened since they've sold the company, but as far as the product itself is concerned, there isn't anything that I would suggest needs improvement. If I'm being picky, Kerio Connect uses a proprietary, mappy atom for Outlook, and it would be nice if they used a native mappy connection instead, but that's the only additional feature that I would like to see in its next release. If they have native Outlook map integration, that would be great, but other than that, it's got all the functions that I think a mail server should have.
Read full review
AP
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 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."
"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 security and privacy because you installed it on your server, within your company premises, not in the cloud."
"We have contacted technical support a handful of times and received some assistance."
"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."
"It's relatively simple to use."
"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."
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

"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."
"The search and archiving documentation capabilities need to be stronger."
"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"
"KerioConnect is stable as long as you use a strong password."
"KerioConnect continues to improve with regular updates throughout the year. They must be added to the roadmap, which requires approval."
"You cannot integrate with other services like Google Docs, Google Assistant, Google Calendar, etc."
"Having a native Outlook map integration would make Kerio Connect better."
More KerioConnect cons
"One improvement could be the integration between ProtonMail and Proton Pass, allowing sharing of specific secrets via email."
"I think it is good but I feel that only tech-savvy people use ProtonMail. It is not that popular among other people."
 

Pricing and Cost Advice

"The pricing is about $3 per mailbox per month."
"KerioConnect has a first-time cost and yearly subscription. It is not expensive."
"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."
Information not available
report
See which vendors are best for you
Use our free recommendation engine to learn which Email Applications solutions are best for your needs.
See recommendations
865,384 professionals have used our research since 2012.
 

Top Industries

By visitors reading reviews
Computer Software Company
14%
Comms Service Provider
11%
Manufacturing Company
8%
Retailer
6%
Computer Software Company
17%
Comms Service Provider
15%
Educational Organization
11%
Manufacturing Company
6%
 

Company Size

By reviewers
Large Enterprise
Midsize Enterprise
Small Business
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?
KerioConnect has a first-time cost and yearly subscription. It is not expensive.
See all answers
What needs improvement with KerioConnect?
KerioConnect continues to improve with regular updates throughout the year. They must be added to the roadmap, which requires approval. In larger organizations, the server's capabilities and the da...
See all answers
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

Microsoft Exchange vs KerioConnect Logo
Microsoft Exchange vs KerioConnect
Compared 49% of the time
Zimbra Collaboration vs KerioConnect Logo
Zimbra Collaboration vs KerioConnect
Compared 28% of the time
IceWarp vs KerioConnect Logo
IceWarp vs KerioConnect
Compared 9% of the time
Microsoft Exchange Online vs KerioConnect Logo
Microsoft Exchange Online vs KerioConnect
Compared 8% of the time
Google Workspace vs KerioConnect Logo
Google Workspace vs KerioConnect
Compared 5% of the time
More KerioConnect Competitors
Google Workspace vs ProtonMail Logo
Google Workspace vs ProtonMail
Compared 43% of the time
Zoho Mail vs ProtonMail Logo
Zoho Mail vs ProtonMail
Compared 17% of the time
Microsoft Exchange vs ProtonMail Logo
Microsoft Exchange vs ProtonMail
Compared 11% of the time
Microsoft Exchange Online vs ProtonMail Logo
Microsoft Exchange Online vs ProtonMail
Compared 10% of the time
Atomic Mail vs ProtonMail Logo
Atomic Mail vs ProtonMail
Compared 8% of the time
More ProtonMail Competitors
 

Product Reports

Buyer's Guide
KerioConnect
August 2025
KerioConnect reportDownload KerioConnect product report
Buyer's Guide
Email Applications
August 2025
ProtonMail reportDownload 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
July 2025
Free Report: KerioConnect vs. ProtonMail
Find out what your peers are saying about KerioConnect vs. ProtonMail and other solutions. Updated: July 2025.
DOWNLOAD NOW
865,384 professionals have used our research since 2012.
See our KerioConnect vs. ProtonMail report.
See our list of best Email Applications vendors.

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.