Classic Outlook is still the best choice for heavy Microsoft 365 users on Windows, while eM Client is the friendliest all-rounder and Thunderbird is the best free option for privacy-minded users. Microsoft says classic Outlook for Windows will be supported until at least 2029, so it is not vanishing tomorrow [source: Microsoft].
TLDR: Pick Classic Outlook if your workday lives inside Exchange, Teams, shared calendars, and Microsoft 365. Pick eM Client if you want Gmail, Outlook.com, calendars, contacts, and chat in one clean app without much setup pain. Pick Thunderbird if you want a free desktop email app and do not mind spending 20 minutes tweaking it. For example, if you handle 80 emails, 10 meeting invites, and 3 shared mailboxes per day, Classic Outlook will usually save the most time.
Best overall: Classic Outlook
Classic Outlook wins for business users because it handles complex email work better than the others. Shared mailboxes, rules, mail merge, offline access, categories, signatures, calendar booking, and Exchange features all feel mature. Not flashy. Just dependable.
If your company uses Microsoft 365, this is the obvious pick. Outlook understands corporate email habits. It works well with Word, Excel, OneDrive, Teams, and SharePoint. You can drag an email into a task, accept a meeting in two clicks, and search years of mail without feeling lost.
The catch is that Outlook can feel heavy. It may take longer to open than eM Client or Thunderbird, especially on older laptops. It also has a lot of menus. Some are useful. Some feel like they came from three different decades. Honestly, it feels like Microsoft keeps adding rooms to the same old house.
- Best for: Microsoft 365 users, offices, managers, admins, power users.
- Big strength: Calendar, rules, Exchange, shared mailboxes.
- Big weakness: Can feel bloated and busy.
- Price: Usually part of Microsoft 365 plans.
Best balanced choice: eM Client
eM Client feels like the email app many people expected Windows Mail to become. It is clean, quick, and easy to understand. It supports Gmail, Outlook.com, iCloud, Yahoo, Exchange, IMAP, and POP. It also includes calendar, contacts, notes, tasks, and chat.
The setup is smooth. Add a Gmail account, sign in, and your mail and calendar appear without much drama. The interface is modern but not weird. You can find what you need fast. That sounds basic, but email apps often make simple things strangely annoying.
eM Client is also good for people who have accounts spread across services. One Gmail account for personal life. One Outlook account for work. Maybe an iCloud calendar. eM Client brings them together better than Thunderbird for most casual users.
It drives me crazy that some useful features sit behind the Pro version. The free version is fine for basic use, but it has limits. If you need many accounts or commercial use, expect to pay. Still, the paid version is often worth it if you want less friction.
- Best for: Home users, freelancers, small teams, Gmail plus Outlook users.
- Big strength: Simple setup and polished design.
- Big weakness: Free version has limits.
- Price: Free tier available, paid Pro version for heavier use.
Best free pick: Thunderbird
Thunderbird is the best choice if you want strong email features without paying. It is open source, widely used, and packed with tools. It supports IMAP, POP, calendars, address books, filters, tags, encryption, and add-ons.
Thunderbird is great for people who like control. You can adjust layouts, install extensions, create deep filters, and manage several inboxes. It also respects users who do not want their email app tied to a giant software subscription.
But Thunderbird is not the smoothest app out of the box. Setup is better than it used to be, but it still feels more technical than eM Client. Some menus need patience. Some add-ons break after major updates. Expect to waste time on small fixes if you like everything neat.
- Best for: Budget users, privacy fans, Linux style power users on Windows.
- Big strength: Free, flexible, open source.
- Big weakness: Less polished and less business friendly.
- Price: Free.
Which one is easiest to use?
eM Client is the easiest for most people. Its layout is clear. Search is simple. Account setup is fast. If you are moving from a webmail inbox, it feels natural.
Classic Outlook is easy only if you already know Outlook. New users may feel buried under buttons. Still, it becomes very efficient once you set rules, views, and folders.
Thunderbird is easy enough for email basics. For advanced use, it asks more from you. That is not always bad. It just depends on your patience.
Which one is best for calendars?
Classic Outlook wins here. Its calendar tools are still hard to beat for office work. Scheduling meetings, checking attendee availability, booking rooms, and managing shared calendars all feel stronger.
eM Client comes second. It handles Google Calendar and Outlook calendars well. For personal life and freelance work, it is more than enough.
Thunderbird has calendar support, but it feels less refined. It works. It just does not feel as smooth when meetings get messy.
Final verdict for Windows users
Choose Classic Outlook if email is part of your job and your company uses Microsoft 365. It is the strongest tool for serious work, even if it feels heavy at times.
Choose eM Client if you want the best mix of comfort, looks, and features. It is the app I would give to someone who wants desktop email without a training session.
Choose Thunderbird if price matters most or if you want an open source app with lots of room to customize. It is not the prettiest option, but it is capable and honest.
The short answer: business users should pick Classic Outlook, most home users should try eM Client, and free software fans should install Thunderbird first.
