Set up Proton Mail Bridge for IMAP and SMTP
Find the local Bridge credentials, ports, and TLS requirements; learn when Proton’s SMTP token is send-only.
Install and open Proton Mail Bridge
- With an eligible paid Proton Mail plan, install Proton Mail Bridge on the same Windows or macOS computer as AeroMailer.
- Sign in to your Proton account inside Bridge. Select the mailbox in Bridge and open its mail-client configuration details.
- Copy the displayed username, Bridge-generated password, server, ports, and security mode. Do not paste your Proton webmail password into AeroMailer.
Enter the local settings
- Choose Proton Mail (Bridge) in AeroMailer’s Add Account. The common host is
127.0.0.1; use the exact settings Bridge shows. - Default IMAP:
1143, STARTTLS. Default SMTP:1025, STARTTLS. If your Bridge uses different ports or SSL/TLS, choose the security type first and then re-enter the actual ports; changing security can reset a port field. - For IMAP use
INBOXunless Bridge exposes a different mailbox you intentionally want to read. Proton does not offer POP3.
Check certificate trust and test
Bridge uses its own local certificate. If AeroMailer rejects it, follow Proton’s Bridge certificate guidance and your operating system’s trust procedure for the verified local Bridge certificate only. Never share the exported private key or turn off certificate validation. If trust still fails, use a Proton-supported Bridge client or contact support. Keep Bridge running and signed in whenever AeroMailer needs to send or receive.
Optional: send only with a Proton SMTP token
If your paid account has an eligible custom-domain address, Proton’s SMTP submission guide shows how to generate a token under Settings → All settings → IMAP/SMTP → SMTP tokens. In AeroMailer use Custom → SMTP only, smtp.protonmail.ch, 587, STARTTLS, with that address as the username and the token as the password. This token does not receive mail and is not the local Bridge password.
