By Manish, who makes LocalInbox · Facts checked October 2026
In short
Thunderbird is a free, open-source mail app from the Mozilla family, for Windows, Mac and Linux, with an Android app. It has no built-in AI writing or summaries. LocalInbox is a native Mac app that sorts, summarises and drafts with Apple's on-device model or a model you run in Ollama or LM Studio, and costs a one-time $19 to $49.
At a glance
| Feature | LocalInbox | Thunderbird |
|---|---|---|
| Price | One-time licence: $19 early access, then $49 | Free (donations welcome) |
| Where AI runs | Apple's on-device model, or a model you run in Ollama or LM Studio, on your Mac | No built-in AI |
| Accounts | Gmail, iCloud, Yahoo, AOL, Fastmail, Zoho, GMX, Proton Bridge, any IMAP | Any IMAP or POP account |
| Open source | No | Yes |
| Platforms | Mac | Windows, Mac, Linux, Android |
When LocalInbox is the better choice
- You want mail sorted and summarised for you, with AI that stays on your Mac.
- You want a native Mac app: menu bar, Spotlight, Shortcuts and Focus filters.
- You want phishing warnings that explain why.
When Thunderbird is the better choice
- You want a free, open-source mail app.
- You use Windows or Linux too and want the same app everywhere.
- You use an Outlook.com, Hotmail or Microsoft 365 account: LocalInbox's Microsoft sign-in isn't available yet.
Sources
Facts about Thunderbird were checked in October 2026 and can change; check its website for current prices and features. Facts about LocalInbox come from its own documentation.
Questions
Is LocalInbox open source like Thunderbird?
No. LocalInbox is a paid app made by one independent developer. Its privacy page lists every connection the app makes, and its AI runs on your Mac.