What is an app password?
An app password is a separate, randomly generated password that you create in your email account so that one specific app can sign in without using your main password.
App passwords exist because of two-factor authentication. Once your account asks for a code as well as a password, an app that signs in over IMAP or SMTP has no way to enter that code. An app password solves this: you generate it once in your account's security settings and paste it into the app in place of your normal password.
Why they are useful
Each app gets its own password, so you can revoke one app's access without affecting anything else or changing your main password. Your main password is never shared with the app.
Not every provider offers app passwords, and some business accounts have them switched off by an administrator. Look for "app password" or "app-specific password" in your provider's security settings or help pages.
App passwords and inboxr
inboxr connects to a mailbox with an IMAP and SMTP username and password. If your provider enforces two-factor authentication, enter an app password in the password field instead of your normal password. If a normal password fails the Test connection check, an app password is the first thing to try. Providers that allow only OAuth sign-in for third-party apps may not work with a password connection.