MXDeck vs Thunderbird
Thunderbird is free, open source, part of the Mozilla family, and runs on Windows, macOS, Linux and Android. It does almost everything, and you can make it do the rest with add-ons. MXDeck does much less, on purpose: a native Mac app for one job, keeping many domain mailboxes readable and healthy.
Facts about Thunderbird are as of November 2026 and link to Thunderbird’s and Mozilla’s own pages in the sources. MXDeck is in development; nothing below says it is out.
Pick Thunderbird if
- You want free and open source. Thunderbird costs nothing, is funded by donations, and its code is open. MXDeck’s code will be published under the FSL, a source-available licence, and the app has paid plans above 3 domains.
- You use more than a Mac. The same client runs on Windows and Linux, and Thunderbird has an Android app. MXDeck is Mac only.
- You need POP3 or Exchange. Thunderbird supports POP3 and IMAP, added native Exchange (EWS) email in version 145 and Microsoft Graph in version 154. MXDeck is IMAP and SMTP only.
- You want filters, calendar and contacts in one place. Thunderbird has message filters, tags, calendars and address books. MXDeck has no rules and no calendar.
- You sign in to Outlook.com. Microsoft’s own help page says Thunderbird supports the modern (OAuth2) sign-in Outlook.com now requires. MXDeck has no OAuth sign-in yet.
Pick MXDeck if
- You have 10 to 30 mailboxes to add. MXDeck imports a YAML or JSON list in one go and verifies every mailbox, so you see at once which password or server is wrong.
- You reply from many domains. Every message has a coloured tag for its mailbox, and a reply always goes out from the mailbox the mail arrived in.
- You want to know when a domain’s mail breaks. MXDeck grades each domain A to F on MX, SPF, DKIM, DMARC, TLS, blacklists and reverse DNS, shows how to fix what is wrong, and notifies you when a grade drops.
- You prefer a light native Mac app. MXDeck is built only for macOS, with macOS notifications, a menu bar icon and passwords in the macOS Keychain. No analytics; it talks only to your mail servers and api.mxdeck.com.
MXDeck is still being built. Threads and undo send are in. Send later, Remind me and drafts synced to the server’s Drafts folder are coming. Spam filtering is left to your server on purpose.
Feature by feature
| Feature | MXDeck | Thunderbird |
|---|---|---|
| Status | In development, beta for the waitlist first | Shipping |
| Price | Free up to 3 domains; paid plans from $6/month (planned) | Free, funded by donations |
| Open source | FSL (source-available), to be published | Yes |
| Windows, Linux, Android | No | Yes |
| IMAP / SMTP mailboxes | Yes | Yes |
| POP3 | No | Yes |
| Exchange | No | Yes EWS since 145, Microsoft Graph since 154 |
| Outlook.com sign-in (OAuth) | No needs OAuth sign-in, not built yet | Yes |
| All mailboxes in one window | Yes | Yes Unified Folders |
| Bulk import of mailboxes from a file | Yes YAML/JSON, each mailbox verified | No |
| Domain mail-health grade (MX, SPF, DKIM, DMARC, TLS, blacklists) | Yes A–F grade, alert when it drops | No |
| Filters / rules | No | Yes |
| Calendar and contacts | No | Yes |
| Add-ons | No | Yes |
| Native macOS interface | Yes built for macOS only | Cross-platform interface |
| Where your mail goes | Direct to your mail servers; only DNS checks via api.mxdeck.com | Thunderbird says it collects no personal data |
“No” means we did not find the feature in the vendor’s official documentation as of November 2026. “Coming” means it is being built for MXDeck and is not in the app yet.
Privacy: close, with one difference
On privacy the two are close. Thunderbird says it does not collect personal data, and neither does MXDeck. The difference is the health check: MXDeck asks api.mxdeck.com to look up public DNS records for your domains, which is how it can grade SPF, DKIM, DMARC and blacklists. It never sends mail or passwords there.
You can try that check now, without the app: the free mail health checker grades up to 25 domains. For the wider setup, read how to manage email for many domains, or see the other comparisons.
Questions
Is Thunderbird good for many email accounts?
Yes, it handles many accounts and has a unified inbox, filters, tags and calendars. It is free and open source. What it does not do is check each domain’s DNS or let you add thirty mailboxes from one file.
Does Thunderbird support Exchange now?
Yes. Thunderbird 145 added native Exchange Web Services (EWS) email support in late 2025, and Thunderbird 154 added Microsoft Graph for Microsoft 365 in 2026. MXDeck supports neither.
Can I keep Thunderbird and use MXDeck too?
Yes. Both use IMAP against the same server, so read, moved and deleted messages stay in sync between them.
Is MXDeck available now?
Not yet. The Mac app is in development and the waitlist gets the beta first.
Sources
Checked in November 2026.
- Thunderbird: home page (free, open source, donations, platforms, unified inbox, filters, calendar, no personal data collection)
- Mozilla Support: FAQ changing IMAP to POP (IMAP and POP3 accounts)
- Thunderbird blog: Thunderbird adds native Microsoft Exchange email support (version 145, EWS)
- Thunderbird 145 release notes
- Thunderbird blog: Microsoft Graph API support (version 154)
- Microsoft: Modern authentication now needed for Outlook.com in non-Microsoft apps
One Mac inbox for all your domains. MXDeck is in development. Join the waitlist and get the beta first.
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