Two Paths to Private and Secure Email Communication
The internet landscape keeps evolving, and digital privacy has been one of the top concerns
for many users. Working with emails calls for the right productivity tools - however, if
security and privacy are not part of the package, many seemingly good deals can go sour
pretty fast.
Both eM Client and Proton are well-established European companies delivering secure and
private email and productivity tools. Proton was
established in 2014 in Switzerland, and the first eM Client app was
released in 2007 in the Czech Republic. While differing in their approaches, both brands
share the same goal of giving you control over your data without compromise.
In this article, we will dive into what eM Client and Proton can provide and how they
compare in features, pricing, and long-term value.
eM Client and Proton: Same Objective, Different Methods
What can you expect from eM Client and Proton? Proton puts privacy at the center of everything - it's a powerful ecosystem of separate tools - Proton Mail, Proton Calendar, Proton VPN, Proton Drive, Proton Password Manager, and more. On the other hand, eM Client is a unified email client and productivity platform - it will aid you in managing your emails, calendars, tasks, contacts, and notes in one place across platforms, including a full-fledged mobile app. In the eM Client desktop app, you will also find a dedicated section where you can access all your chats, such as Microsoft Teams, Slack etc. eM Client is not an email service provider - it is (as the name suggests) a secure email client, giving you the flexibility to use multiple email service providers - and to switch to a different one anytime or even combine different services.
eM Client Versus Proton: Features Overview
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Email
eM Client does not offer email servers, but it will give you a unified inbox for your email accounts from different providers, PGP or S/MIME encryption and digital signatures, rules and filters, Quick Actions, Quick Texts, and other advanced emailing features. The app features calendar, contacts, tasks, notes, and chat sections as well. A nice bonus is the ease with which settings import and export work between different devices using the QR code or .xml file import/export feature.
Proton provides its own secure encrypted email service known as Proton Mail. The premium plans include the ability to use custom domains and Proton Mail Bridge, which is required for IMAP access to your Proton Mail account. While Proton does offer a desktop app for its own services, like Proton Mail and Calendar, you are locked out of using external apps, unless you pay for a Proton subscription and use the Proton Mail Bridge.
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Mobile App
eM Client's mobile app matches the desktop version's features and lets you manage your mail, calendar, tasks, contacts, and notes in one place, which is unprecedented on the iOS and Android platforms. It's a handy management tool for all your accounts and their services and includes the same encryption features as the desktop app for an extra level of protection.
Proton offers separate mobile apps dedicated only to its own services - Proton Mail, Calendar, Drive, VPN, Pass, Proton Wallet, Meet, and Authenticator. Since there is no Proton Bridge mobile app, you won't be able to connect your Proton email account to a different email client on mobile (including eM Client), even if you prefer its feature set to that of the Proton Mail app.
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AI Integration
eM Client delivers built-in AI features - allowing you to use AI to send quick replies, proofread, or fine-tune the tone and phrasing of your emails. Since the Artificial Intelligence features are available directly in the app, it's optimal for productivity and smooth workflow. The current provider of AI is OpenAI, so prompts are subject to the OpenAI privacy policy, but your data is not used for further training of the Language Model. You can read more about the AI features in eM Client here.
Proton offers an AI writing assistant in its Mail app. It's possible to enable and run it either locally or on Proton servers. It can proofread, expand, or shorten your messages or change between friendly and formal tone when you compose a new message - prompting to write a new message is available as well. Then there is Proton Lumo, a standalone, early-stage AI assistant with zero-access encryption, Ghost Mode (ephemeral chats), encrypted file uploads, and optional private web search.
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Privacy & Security
eM Client app (both desktop and mobile) supports PGP and S/MIME encryption and digital signatures, and secure OAuth authentication. It offers local-only storage options and tracking pixel blocking. User data is kept locally on your device - eM Client never has access to your accounts or personal information. Additionally, the password-protected startup feature will help you block any unauthorized access to the desktop app. The eM Client team always keeps on top of all security standards, passing assessments from cybersecurity auditors like Leviathan Security or TAC Security.
Proton uses end-to-end encryption by default for messages sent between Proton users and stores them with zero-access encryption - that means they cannot be read even by Proton itself. Encrypted messages can be sent to external recipients via the Password-protected Emails feature or using their public key. Based in Switzerland, Proton protects your data under Swiss law. It is open-source, allowing for independent audits. Two-factor authentication is possible via Proton Authenticator or external apps like Google Authenticator. An additional layer of privacy can be achieved with the use of Proton's own VPN app.
Long-Term Value: Subscription vs Lifetime
Although both companies offer free plans, using the full spectrum of the features of either Proton or eM Client comes with a cost. So let's talk finances.
Proton's paid plans include multiple Proton services (Mail, Calendar, Drive, VPN, Pass, etc.) but are limited to subscription only - there is no one-time payment option available. The scope of each service varies based on the subscription tier. You should be sure that a full Proton-only solution is the right choice for you before you decide to go with the Proton ecosystem.
Proton personal subscription plan starts at around $50 per year (if you subscribe for 1 year). This plan is going to add up to around $250 in 5 years. The most affordable business subscription plan is around $84 per year for 1 user, and will cost you around $400 in 5 years.
eM Client offers two payment options: subscription or one-time license purchase. You can pay an additional fee to make your license valid for all future versions of the app. eM Client does not bundle multiple services (except the AI Add-on being part of every subscription plan), but since the pricing is quite affordable, it gives you the leeway to invest the money you save in a separate server solution, allowing you to keep your options open for combining various services.
eM Client will be around $40 per year for the Personal plan, costing you $200 in 5 years. The Business plan for 1 device costs about $50 for a year and $250 for 5 years. Although we are using the example of a 1-device business license here, one major advantage of the Business license is the possibility to decide exactly how many devices you wish to purchase. Significant bulk discounts are available as well - for example, if you go with 10 devices, each device will only cost you around $20 per year.
Where eM Client really shines is the one-time payment options, though. Even if you opt for lifetime upgrades, the one-time payment for a Personal license costs around $150 - and you own it forever. The one-time Business license for 1 device will cost approximately $180, including lifetime upgrades and no additional future costs.
Customer Perspective
When deciding which service to go with, especially long-term, we cannot overlook the actual user experience. While there are multiple review platforms, let's take a look at the well-known and respected Trustpilot.
As of September 2025, user evaluations of the eM Client app are overwhelmingly positive, with an average of 4.2 stars (based on nearly 11,000 reviews). They like the easy setup, user-friendly and clean layout, and smooth sync across various services and accounts. Additionally, technical support is considered helpful and quick to respond. Negative reviews are typically addressed within 1 week at most.
At the same time, both Proton and its email service, Proton Mail, do not rank as highly, with 2.7 and 2.2 stars average ratings (based on approx. 250 and over 1,000 reviews, respectively). Proton replies to most negative reviews within 24 hours, but some users still find the customer support rather lacking. It does seem that many individuals find Proton easy enough to use without additional assistance, however, it may not be the solution for companies where dependable support is crucial - they might want to explore alternatives to Proton Mail instead.
Use Cases: Which One Is Right for You?
Proton is a suitable option for anyone seeking an encrypted email solution with a fully integrated privacy ecosystem with email, VPN, storage solution, password manager, and more. While Proton offers a complete privacy suite, it comes at a steeper price and allows less flexibility to use multiple providers.
eM Client is a powerful unified email client with AI, calendar, tasks, and cross-provider support. It might fit you if you already use multiple services and want a safe, private, and user-friendly way to manage all of them.
In case you want to take advantage of Proton Mail but don't want to rely solely on Proton as the service provider, you can pair eM Client with Proton Mail via Proton Bridge to enjoy the benefits of both.
Proton and eM Client are both powerful tools that respect your privacy and aim to keep your data secure. Proton is a secure services ecosystem, while eM Client will help you to stay productive without compromising flexibility or your data. Deciding which option is better ultimately depends on your specific needs. However, the future of privacy and productivity seems to be mixing and matching tools based on what they can do best.