Skip to content 
The comparison of the best E-mail clients 2025 offers many new functions, stronger security mechanisms and sensibly integrated AI functions. This article provides practical guidance for users who want to find the right program for efficient email management in a private or professional context. Modern requirements include not only sending and receiving emails, but also managing calendars, tasks and chats as well as dealing with encryption and possible collaboration tools.
Key points
- Operating systemsMany clients run cross-platform, some are only available for Windows or Apple.
- Scope of functionsMail, calendar, tasks and chats are increasingly flowing together.
- SecurityPGP encryption, certificates and secure connections are standard today.
- CustomizationThemes, add-ons and automations enable perfect workflows.
- CostsBetween free and premium - the choice depends on the area of application.
Why is the choice of email client so important? In times when communication is becoming ever faster and more complex, the client should be reliable and optimally support the personal workflow. Functions such as extensive search filters, offline availability or automatic sorting save a lot of time in everyday life. Data protection is also becoming increasingly important, which is why robust encryption or good spam filter mechanisms have become almost indispensable.
Market overview: A direct comparison of the best email clients in 2025
I have examined the most popular programs in terms of performance, scope and user guidance - resulting in a direct overview of the features of the top candidates. What is particularly striking is that the favorites cover different user groups, from purists to power users. Another important question is how well the tool can be integrated into existing systems. Anyone using Microsoft 365 or Google Workspace, for example, needs a client that specializes in these services or can at least integrate them reliably.
| Place | E-mail client | Operating systems | Advantages | Disadvantages | Price |
|---|---|---|---|---|---|
| 1 | Mailbird | Windows | User-friendly, integrations, layouts | Windows only, many functions for a fee | from 0 €, Pro from 3 €/month |
| 2 | Thunderbird | Win, Mac, Linux | Open source, add-ons, free of charge | Old-looking surface | free of charge |
| 3 | eM Client | Win, macOS | All-in-one, AI, PGP, modern | Free version very limited | from 0 €, Pro from 49,95 € |
| 4 | Postbox | Win, macOS | Filter, cloud, quick search | No free version | from 29 €/year |
| 5 | Airmail | macOS, iOS | Apple-inspired, customizable | Only for Apple, for a fee | from 26,99 € |
| 6 | Canary Mail | macOS, iOS | End-to-end encryption, focus mailbox | Platform limited | from 19,99 € |
| 7 | Mailspring | Win, Mac, Linux | Open source, fast, lightweight | Limited free version | from 0 €, Pro from 8 €/month |
| 8 | Claws Mail | Win, Mac, Linux | Speed, low resource consumption | Hardly any comfort functions, no mobile counterpart | free of charge |
The table provides a quick overview. However, there are many more functions and aspects behind it that you should keep in mind when making your decision. For example, the question of whether the program is used on many end devices is relevant - anyone who frequently switches between desktop, laptop or tablet needs reliable synchronization. Some clients, such as Thunderbird or Mailspring, are particularly versatile here, as they run across platforms and offer great community support.
Mailbird: Simple, clear and ideal for Windows
Mailbird brings structure to my daily communication. The software shines with a unified inboxnumerous plugins and a tidy design. I particularly like the links to tools such as Slack, Google Calendar or WhatsApp - all in one screen. Mailbird supports keyboard operation, favorites panels and can be customized visually. The only limitation is the Windows platform lock-in.
If you use Mailbird in Comparison of all top email clients If you take a closer look, you can clearly see that this application is one of the most versatile solutions for everyday use. The uniform interface allows the flood of emails to be channeled efficiently. Another plus point is the option of setting daily targets for processing emails or displaying short reminder messages so as not to lose sight of certain conversations.
For business users, the integrations with CRM systems (such as Pipedrive or HubSpot, if these are available in the Pro version) prove to be useful. It is possible to see directly in the client which contacts match existing customer data. This speeds up work processes enormously and creates a kind of central communication cockpit.
Thunderbird: Open, independent, reliable
Thunderbird has been my favorite open source client for years. The community-oriented development regularly brings new features without compromising on quality. Points such as data protection or compatibility. Particularly noteworthy are the flexible add-on structure and the advanced spam filter. Calendar, task management and even chat functions can be activated in an integrated manner. For technology enthusiasts, I recommend the option to manage PGP encryption manually.
The "old-looking interface" may put off some modernization fans at first, but thanks to themes and numerous settings, Thunderbird is surprisingly flexible. In addition, the software supports huge mailboxes and good management of folders or filters. So anyone who manages several e-mail addresses or relies on an extensive folder structure will find Thunderbird a patient companion.
The option to work with advanced filters and keywords should also not be underestimated: Prioritized emails can be highlighted directly or automatically sorted into subfolders. When it comes to synchronization with smartphones, IMAP is generally used - the Thunderbird account cannot be used as an app on the go, but the data remains stable and always accessible.
eM Client: Modern communication on a new level
eM Client impressed me with its functional depth and modern design in equal measure. In addition to AI-supported writing - for example for automatic translation - the client seamlessly integrates tasks, meetings, contacts and mail traffic. I particularly like using it in combination with Gmail and Microsoft 365, as it takes just a few minutes to set up. PGP and S/MIME encryption are also integrated directly into the interface.
For anyone who writes a lot for work, manages appointments and regularly sends large attachments, eM Client offers an intuitive workplace structure. The option of displaying conversations in chat style is also helpful, so that exchanges with customers or colleagues remain particularly clear. In recent years, the developers have also worked on performance and stability: even large mailboxes with many thousands of emails remain responsive and easy to search through.
Another strength: the integrated contacts make it very easy to create distribution lists or automatic reply templates. So if you are planning extensive email campaigns or need to send the same texts repeatedly to different recipients, you can save an enormous amount of time here.
Postbox and Airmail: Premium clients in comparison
Postbox relies on powerful filter functions, rule wizards and a Effective searchto organize even large mail volumes. The user interface is clear and work-focused. The disadvantage: there is no permanent free version. Airmail is aimed more at Apple users with an affinity for design. The client shines with smooth scrolling, intelligent sorting and integration with apps such as Dropbox, Evernote or Asana. Anyone looking for mail management with fast access and style will find their favorite in Airmail.
What is particularly remarkable in Postbox is how deep the search operators can go: For example, you can filter by time periods, keywords or senders and find the conversation you are looking for within a few seconds. This makes Postbox particularly interesting for power users who are constantly processing large volumes of emails. So-called "response templates" also offer a kind of quick module system for frequently required text modules. This is a real efficiency booster, especially in professional environments.
Apple users, on the other hand, appreciate Airmail not only because of its stylish design, but also because of its seamless integration into the operating system. Numerous gestures and keyboard shortcuts enable precise fine control. Anyone who finds Apple's own mail app too simple, but Outlook too overloaded, could find the ideal middle ground in Airmail. In particular, the simultaneous handling of several accounts is very intuitive.
Canary Mail & Mailspring: focus on security and speed
With Canary Mail, users benefit from End-to-end encryption even in the standard version. The client distinguishes important from unimportant and sorts automatically - ideal for people who work with sensitive information. Mailspring takes a different approach: the open source model allows fast synchronization, a great interface and high performance even with weak hardware. Linux fans in particular appreciate the low system load.
Canary Mail attaches great importance to the user retaining their privacy. The encryption keys can be managed locally, which makes it difficult for external parties to read them. This is a strong argument, especially in law firms or start-up environments, where a lot of focus is placed on security. On the other hand, Canary Mail feels rather minimalistic for some users, but this can be an advantage if you don't want to be distracted by unnecessary functions.
Mailspring, on the other hand, deserves a mention because it has a useful contact manager in addition to its attractive appearance and fast operation. This automatically recognizes duplicate entries and can help to clean them up. This saves a lot of manual work for anyone who has to manage numerous e-mail addresses and contacts.
Claws Mail: For purists with a clear vision
I recommend Claws Mail to anyone who values speed and can do without visual gimmicks. The client shows that Core functions such as IMAP support, MIME processing and filters are all you need to work productively. Claws Mail starts in less than a second, requires hardly any memory and still looks complete. The disadvantages are the old-fashioned environment and the lack of mobile apps. Ideal for older systems or developers.
Programmers and Linux power users in particular will appreciate Claws Mail, as the source code is kept lean and customizations can often be made directly. It is also easy to integrate your own scripts and adapt the client to your own workflows. So if you are not interested in countless cloud integrations and simply need a high-performance, stable email program, you will find an almost timeless tool here.
Microsoft Outlook & alternatives for companies
Outlook remains a fixed standard for companies - especially due to the Office integration. For small companies or freelancers, however, the price can be high, especially if you don't need the whole Microsoft 365 environment. Many therefore switch to eM Client or Mailbird. These not only offer almost the same range of functions, but also incorporate modern concepts such as AI suggestions or Slack linking.
With Outlook, the shared calendar and links to other Office apps such as Teams, Word or Excel are seamlessly integrated - which can have both advantages and disadvantages. In large corporations, this is often indispensable, but in smaller teams it can sometimes seem too complex. The IT department also plays a role: those who have to adhere to regulations or require special support are often better off with Microsoft solutions. In private or agile companies, on the other hand, leaner alternatives are worth considering.
Helpful distinctions between IMAP and POP3 protocols can be found in this compact Technical overview of mail protocols.
Webmail alternatives 2025: Quick access in browser environments
Many users today work completely without a local client - webmail services such as Roundcube, RainLoop or SnappyMail allow mail management in the browser. Advantages: low system requirements and location-independent access. Limitations exist with layout customization, offline work or ease of use. Especially in combination with Exchange or IMAP hosting, webmail services can be a lean alternative.
If you would like to find out more, you will find Compilation of current webmail apps There are quite clear differences between modern and classic solutions. Today, webmail solutions often include access to calendars, contacts and cloud storage as long as the corresponding server setup is available. However, they are less flexible in terms of customization; add-ons or theme changes are usually severely restricted - if at all.
Browser offerings are a good choice, especially for occasional users who simply want to ensure that they can access their emails anytime and anywhere. However, those who need intensive filter rules, a multi-level project structure or offline access are still better served with dedicated clients.
Another aspect for webmail users is data storage: often everything is stored on the server, which has the advantage that no mail is lost in the event of a device failure. On the other hand, problems can occur without an internet connection. So if you are regularly on the move or have to make do with slow networks, you might enjoy locally installed clients more.
Concluding overview: What suits whom
The requirements are different - and so is the choice. Those who insist on security features should look at Canary Mail or eM Client. Claws Mail or Mailspring offer speed and resource conservation. If your system runs on Windows, then Mailbird macOS users choose Airmail for its elegant design - or Canary for more privacy. Thunderbird provides a reliable, free entry point for all platforms with maximum customization freedom.
Whether you are an individual, agency or company - choosing the right client is crucial for efficiency in everyday digital life. If you also need professional hosting environments with e-mail integration, the solutions from webhoster.de particularly reliable. Also consider the size of your mail quota, how many accounts you operate and whether local data storage makes sense for you. A clear understanding of your priorities will help you make the final decision:
- Do you need Maximum security? Then use strong encryption programs such as Canary Mail or eM Client.
- Do you value Open source and flexibility? Thunderbird or Mailspring could be your first choice.
- Do you wish Uniform design elements with AI support? Then take a look at eM Client or Outlook.
- Do you like it minimalist and fast? Claws Mail and its resource conservation are remarkable.
For many organizations, it can also make sense to restructure internal communication. Today, emails are not just the sole focus, but part of the overall collaboration and storage landscape. The chosen client should therefore fit into the overall strategy and make work easier in the long term. To do this, check in advance which tools your teams also use. Only if communication, project management and file storage interact smoothly will you have a powerful setup in the long term.
