Mailbird and eM Client are both Windows-native desktop email clients fighting for the same audience: users who want more than Outlook without the complexity of Thunderbird. They are close enough in feature parity that the decision almost always comes down to two things: whether you need a built-in calendar, and whether the Mailbird integrations dock justifies the higher price.
Try Mailbird freeSetup and First Impressions
Both clients install in under five minutes. Mailbird’s onboarding is slightly more polished — Gmail and Outlook OAuth flows are handled with one-click approval. eM Client’s automatic account detection covers more edge cases (Exchange, CalDAV, CardDAV) and has a more powerful initial import wizard.
Mailbird downloads as a standard Windows installer. Run it, add an email account (Gmail via OAuth, Outlook via OAuth, or any IMAP account via server settings), and you’re in the unified inbox in about four minutes. The UI loads fast — roughly 3–4 seconds on a mid-range Windows 11 machine (Intel Core i5-1235U, 16 GB RAM) — and the initial experience is clean and welcoming.
The only friction on the free tier: one account limit. If you have personal and work email, you need to pay before adding the second account. The 14-day money-back guarantee takes the risk out of that commitment, but it is a decision point the onboarding asks you to make immediately.
eM Client also installs cleanly. Its account setup wizard automatically detects IMAP/SMTP settings for most major providers, including Gmail, Outlook, Yahoo, and iCloud. For Exchange and Microsoft 365 accounts, eM Client adds native Exchange support via the Modern Authentication (OAuth 2.0) path — you don’t need an app password or special IMAP settings for corporate Microsoft accounts.
The initial impression is more utilitarian than Mailbird’s. The default layout is denser: mail, calendar, and contacts are visible in the left sidebar from the start, which is useful context but visually busier than Mailbird’s approach of starting with email only.
Free tier comparison: eM Client’s free plan allows two email accounts — an immediate advantage over Mailbird’s one-account limit. For a user with a personal and a work email, eM Client’s free tier covers the core use case at zero cost.
Edge: eM Client for Exchange/corporate accounts and for users who want a free two-account setup. Mailbird for polished onboarding on consumer accounts (Gmail, Outlook.com).
Calendar and Contacts
eM Client has a fully native, built-in calendar and contacts manager with offline sync, CalDAV support, and a task panel. This is the most significant functional difference between the two clients. Mailbird displays calendars only via the integrations dock — no native pane, no offline access.
This is the section where the comparison becomes decisive for many users.
eM Client’s calendar is first-class and built in:
- Full CalDAV and CardDAV sync (Google Calendar, iCloud, Nextcloud, Exchange)
- Offline calendar access — events load even when offline
- Tasks and to-do panel integrated alongside mail
- Meeting invitations handled natively (accept/decline from mail, updates reflected in calendar)
- Multiple calendar overlay, colour coding, week/month/agenda views
- Contact photo sync from Google Contacts, iCloud Contacts
For users who do real calendar management inside their email client — scheduling meetings, checking availability, creating recurring events — eM Client’s calendar is as functional as the Outlook or Thunderbird calendar. It has been the headline differentiator for eM Client for years.
Mailbird’s calendar is an embedded web view:
- Google Calendar opens in the integrations dock as a web app
- Outlook Calendar is accessible the same way
- No offline access — if you’re not connected, the calendar pane shows nothing
- No native meeting invite handling — accept/decline is done in the web view
This is not an oversight in Mailbird’s design; it is a deliberate product choice to keep the core client lean and push calendar access through the integrations panel. The result is acceptable for users who primarily reference their calendar rather than actively managing it. It is noticeably inferior for power calendar users.
Edge: eM Client, significantly. For anyone who uses their calendar actively inside their email client, eM Client’s native calendar is worth the comparison alone.
Integrations and Extensions
Mailbird’s integrations dock supports Slack, WhatsApp, Google Calendar, Asana, Dropbox, and about 30 other tools in a persistent side panel alongside email. eM Client does not have an equivalent integrations panel — it extends via plugins, but the plugin ecosystem is smaller and less curated.
Mailbird’s integrations panel is its headline feature. Slack, WhatsApp, Google Calendar, Todoist, Asana, Dropbox, Instagram, and others sit in a persistent sidebar. You can check a Slack message or look at a Google Calendar event without leaving Mailbird or switching windows. For users whose workflow spans those specific tools, the panel genuinely reduces context switching.
Available integrations as of April 2026 (per the Mailbird app): Slack, WhatsApp, Google Calendar, Outlook Calendar, Asana, Dropbox, Google Drive, Basecamp, Salesforce, Todoist, Trello, Evernote, Wunderlist, ChatGPT, and approximately 15 others. The list does not include every tool, but it covers the popular productivity and communication apps.
eM Client does not have an equivalent dock. It has a plugin marketplace for extensions like email tracking (Mailtrack integration), spam filters, and signature managers, but the ecosystem is smaller and requires more individual configuration. The strength is in the native calendar and contacts — eM Client’s approach is to do those deeply rather than integrate with 30 external tools shallowly.
ChatGPT for email drafting exists in Mailbird (via the integrations panel) and is not native to eM Client.
Edge: Mailbird, for users whose workflow depends on the integrations dock. eM Client, for users who prefer native built-in capabilities over third-party integrations.
Interface and Customization
Mailbird has a more polished default aesthetic with a theme picker, custom backgrounds, and dark mode. eM Client’s UI is functional and professional but more utilitarian — closer to Outlook’s design language than to a consumer app.
Mailbird’s UI is the reason many users originally download it. The default light theme is clean and fast. Dark mode is well-implemented. The inbox layout options (wide view, three-panel, conversation view) are easy to switch between. The keyboard shortcut system is comprehensive — ? opens the shortcut reference from anywhere in the app. The speed reader is a unique feature (pauses and displays words at speed to consume email faster) that has no equivalent in eM Client.
The integrations dock is always visible and can feel cluttered if you have many apps pinned. Hiding individual apps from the dock is supported but requires going into settings for each one.
eM Client’s UI is denser and more information-forward. The default layout shows mail, calendar events, and the unread count for multiple accounts in the sidebar at once. The design language is closer to Outlook 2019 than to a modern consumer app. Dark mode is available and decent but not as refined as Mailbird’s.
Customization ceiling: Mailbird has a theme picker and background images; eM Client has theme colours and density settings. Neither is deeply customizable in the way Thunderbird is with add-ons — but both are more configurable than Outlook.
Edge: Mailbird for visual polish and the “looks like a premium app” feel. eM Client for information density and users who prefer a more conservative, Outlook-like layout.
Pricing
eM Client Free allows two accounts at zero cost. eM Client Pro is ~$39.95/year per device. Mailbird Free allows one account. Mailbird Premium is €73.80 one-time or ~€27.60/year. For a two-account user on a budget, eM Client’s free tier wins outright.
eM Client pricing (per pricing page, verified April 2026):
- Free: Two email accounts, all core features, no time limit. No calendar or contacts limitations.
- Pro (annual subscription): ~$39.95/year per license. Adds: unlimited accounts, VIP support, commercial use rights, additional features.
- Pro (one-time): Available as a lifetime license for approximately $59.95. Pricing has historically been offered at promotional rates.
Mailbird pricing (per pricing page, verified April 2026):
- Free: One email account, Knowledge Base support only.
- Premium (annual):
€27.60/year (€2.30/month billed annually). - Premium (one-time lifetime): €73.80.
See our Mailbird pricing guide for the full breakdown including add-ons.
| Tier | eM Client | Mailbird |
|---|---|---|
| Free accounts | 2 | 1 |
| Paid price (annual) | ~$39.95/year | ~€27.60/year |
| One-time license | ~$59.95 | €73.80 |
| Calendar (built-in) | Yes | No (via dock) |
| Exchange support | Yes | Via IMAP |
| Integrations dock | No | Yes |
For a solo user with two accounts and a tight budget: eM Client’s free tier covers the complete use case. Mailbird’s free tier does not.
For a user who values the integrations dock: Mailbird at €73.80 is a reasonable one-time cost for a daily-use desktop app.
Comparing Mailbird pricing in detail? See Mailbird’s pricing page or read our Mailbird pricing guide.
Verdict
eM Client wins for users who need a built-in calendar, have two accounts to manage on a budget, or work in a corporate Exchange environment. Mailbird wins for users who want the integrations dock, a more polished consumer UI, and Slack/WhatsApp in the same window as email.
After using both clients on Windows 11 for the purpose of this comparison, the verdict is straightforward:
Choose eM Client if:
- You use your calendar actively inside your email client and want full offline sync
- You have exactly two accounts (personal + work) and want a free solution
- You’re on a Microsoft 365 / Exchange environment and want native OAUTH authentication
- The integrations dock is not part of your workflow
Choose Mailbird if:
- Slack, WhatsApp, Google Calendar, and other tools being in one window genuinely saves you time
- UI polish matters — you want something that looks and feels like a modern app, not a business tool
- You’re buying once and want a lifetime license that covers both Windows and Mac
- Email tracking and send-later are part of your workflow
The one thing that makes the decision easy: do you need a real, native calendar inside your email client, or is a web-embedded Google Calendar view acceptable? If real calendar: eM Client. If the dock approach is fine: Mailbird.
Try Mailbird freeWhen Neither Is the Right Answer
- Mac + Gmail only: Mimestream uses the Gmail API natively and is the strongest choice for that combination.
- Linux users: Neither Mailbird nor eM Client has a Linux build. Thunderbird is the answer.
- Team shared inbox: Both are single-user clients. For team email with shared assignment, look at Missive or Front.
- Privacy-first, zero commercial software: Thunderbird is the open-source option.
Also see: Mailbird review 2026, Mailbird vs Thunderbird 2026, Mailbird pricing and plans 2026.
Alexis Dollé, email expert for 10+ years. Founder of Email Tools. I test every email client and utility myself, then write about them the way I’d explain them to a friend — no marketing fluff, no sponsored rankings, every claim sourced.
LinkedInFrequently asked questions
Is eM Client free? — two accounts, no time limit
eM Client has a free plan limited to two email accounts with full access to core features including the built-in calendar and contacts. No time limit. The Pro version (~$39.95/year) unlocks unlimited accounts and commercial use rights.
Does eM Client work on Mac? — yes, since 2021
Yes. eM Client launched a native Mac version in 2021. Mailbird also launched on Mac via the Apple App Store in September 2025. Both clients now support Windows and Mac.
Which is better for a Windows business user: Mailbird or eM Client?
eM Client’s free tier supports up to two accounts and its built-in calendar and contacts work well for solo business users. Mailbird wins for users who need integrations with Slack, WhatsApp, and Google Calendar in a single pane. For Exchange/M365 corporate accounts, eM Client’s native EWS support is smoother than Mailbird’s IMAP-based approach.
Does Mailbird have a built-in calendar? — no, embedded web view only
Mailbird displays Google Calendar and Outlook Calendar via the integrations dock as embedded web apps. There is no native calendar pane, no offline sync, and no native meeting-invite handling. eM Client has a fully native calendar with offline sync.
Can eM Client handle Gmail labels? — yes, via IMAP folder mapping
Yes. eM Client maps Gmail labels to IMAP folders. Changes sync back to Gmail. It is not as seamless as a Gmail-native API client like Mimestream, but labels, stars, and archived mail all work correctly.
Does eM Client have a Slack integration? — no built-in dock
eM Client does not have an integrations dock equivalent to Mailbird’s. There is no built-in Slack panel. If Slack-in-the-sidebar is important to your workflow, Mailbird has it; eM Client does not.