Many IMAP/SMTP clients, like msmtp, fdm, isync, neomutt or mutt can use OAuth2
access tokens but lack the ability to renew and/or authorize OAuth2
credentials. The purpose of oama is to provide these missing capabilities by
acting as a kind of smart password manager. In particular, access token renewal
happens automatically in the background transparent to the user.

The OAuth2 credentials are kept in a keyring provided by any password manager
with a FreeDesktop.org Secret Service compatible API. Some examples of such
password managers are:

    Gnome keyring
    KDE Wallet Manager
    KeePaasXC

Alternatively GNU PG encrypted files can also be used as a backend for storing
credentials.