By Manish, who makes LocalInbox · Facts checked November 2026
Proton makes its own Proton Mail desktop app for macOS 12 or later, on its paid plans; a free plan can try it for 14 days. LocalInbox works with Proton Mail through Proton Mail Bridge, Proton's app that decrypts your mail on your Mac and hands it to mail apps over IMAP. Bridge needs a paid plan too. With LocalInbox, Proton sits in one inbox beside Gmail, iCloud and any IMAP account, and the AI runs on your Mac by default.
Proton Mail on a Mac today
Proton Mail's desktop app runs on macOS 12 or later. It comes with Proton's paid plans; on the free plan you can try it for 14 days.
Other mail apps reach Proton through Proton Mail Bridge, which runs on your Mac, decrypts your mail there and serves it over IMAP and SMTP at 127.0.0.1. Bridge is on Proton's paid plans.
How LocalInbox works with Proton Mail
- It connects to Bridge at 127.0.0.1, IMAP on port 1143 and SMTP on 1025 by default, with the password Bridge shows, not your Proton password.
- Mail goes from Bridge to LocalInbox over a connection on your Mac. Nothing passes through a LocalInbox server.
- Your decrypted Proton mail isn't sent to an AI service. Summaries, suggested replies and Ask your mailbox run on your Mac by default, with Apple Intelligence or a model server you run on it such as Ollama or LM Studio.
- Keep Bridge running while you use LocalInbox. If it isn't, LocalInbox says nothing is answering at the port.
- Proton sits beside your other accounts in one inbox, with one search across all of them.
What LocalInbox adds
What every account gets in LocalInbox, Proton Mail included:
- Unified inbox: One inbox for Gmail, iCloud, Yahoo, Fastmail, Zoho, GMX, AOL, Proton Mail Bridge and any IMAP account, each with its own colour. Native and fast.
- On-device AI: LocalInbox summarises, sorts and drafts your email with Apple's on-device model. No AI cloud unless you add your own key, and no LocalInbox server.
- Ask your mailbox: Ask a question in plain words and LocalInbox answers from your own mail, with numbered sources you can open. It runs on your Mac by default.
- To Reply and smart sorting: LocalInbox sorts mail into Primary, Updates, Promotions and your own categories, and keeps a To Reply mailbox of mail waiting on you.
- Today and the Morning brief: Today lists what needs a reply, what you're waiting on, meetings, deadlines, parcels and trips. The Morning brief sums up important mail, on your Mac.
- Waiting On and Nudge: Waiting On lists mail you sent that hasn't had an answer after three days. Nudge writes a polite follow-up for you to edit and send.
- Phishing warnings: LocalInbox flags suspected phishing and says why: a look-alike address, failed SPF, DKIM or DMARC, a misleading link, or pressure to sign in or pay.
- Search inside attachments: LocalInbox reads the text in scanned PDFs and photos on your Mac, so a receipt or a boarding pass turns up in search.
- Undo Send, Send Later and snooze: Undo Send for up to 30 seconds, Send Later, snooze, and remind me if no reply, for every account. They work even when LocalInbox is closed.
Set up Proton Mail in LocalInbox
- Install Proton Mail Bridge and sign in to your Proton account in it.
- In Bridge, open the account's mailbox details for IMAP and SMTP.
- In LocalInbox, open Settings › Accounts and click Add Account (or use the welcome screen the first time).
- Choose Proton Mail and enter your Proton address.
- Copy the user name and password Bridge shows into LocalInbox and click Add.
Server settings and what to do if it doesn't connect: Proton Mail IMAP and SMTP settings with Proton Mail Bridge.
Sources
Facts about Proton Mail's own apps were checked in November 2026 and can change. Facts about LocalInbox come from its own documentation.
Questions
Should I use Proton's app or LocalInbox?
If Proton is your only account, Proton's own app is made for it. LocalInbox suits you if you also have Gmail, iCloud or other accounts and want them in one Mac app, with AI on your Mac by default.
Is my Proton mail still end-to-end encrypted?
Up to your Mac, yes. Bridge decrypts the mail on your Mac and passes it to LocalInbox over a connection that never leaves the Mac (127.0.0.1).
Does it work on Proton's free plan?
No. LocalInbox needs Proton Mail Bridge, which is on Proton's paid plans.
What does LocalInbox cost?
It's free for 7 days with every feature, with no sign-up or card. Then it's $29.99 once, for up to three devices (Mac, iPhone or iPad), with every 1.x update. There's no subscription.
Can I use Proton Mail in LocalInbox on iPhone?
No. LocalInbox for iPhone and iPad doesn't offer Proton Mail, because Proton Mail Bridge runs on a computer. Your other accounts work there, with the same licence: https://localinbox.app/iphone