In short
To add GMX to LocalInbox, turn on POP3 & IMAP access in GMX (Settings › POP3 & IMAP), then choose GMX in LocalInbox and enter your GMX password, or an app-specific password if you sign in with two factors.
Steps
- In GMX, turn on POP3 & IMAP access under Settings › POP3 & IMAP.
- In LocalInbox, open Settings › Accounts and click Add Account (or use the welcome screen the first time).
- Choose GMX and enter your address.
- Enter your GMX password, or an app-specific password if you sign in with two factors, and click Add.
Server settings
| Server | Host name | Port | Security |
|---|---|---|---|
| Incoming (IMAP) | imap.gmx.com | 993 | SSL/TLS |
| Outgoing (SMTP) | mail.gmx.com | 587 | STARTTLS |
For gmx.net, gmx.de, gmx.at and gmx.ch addresses LocalInbox uses imap.gmx.net and mail.gmx.net.
Troubleshooting
LocalInbox says it can't connect
The message says what to fix: nothing answering at the port, the wrong kind of TLS for the port, an untrusted certificate, an unknown server name, or a timeout. Check the server settings below against the ones LocalInbox filled in.
Questions
Where does LocalInbox keep the password?
In the macOS Keychain on your Mac. It's never written to a file or sent anywhere except your mail server.