A server using OAuth2 auth looks this:
<pre>
...
<incomingServer type="imap">
<hostname>imap.gmail.com</hostname>
<authentication>OAuth2</authentication>
<authentication>password-cleartext</authentication>
<oAuth2>
<issuer>login.yahoo.com<issuer>
<scope>mail-w<scope>
<authURL>https://api.login.yahoo.com/oauth2/request_auth</authURL>
<tokenURL>https://api.login.yahoo.com/oauth2/get_token</tokenURL>
<oAuth2>
</incomingServer>
</emailProvider>
<oAuth2>
<issuer>login.yahoo.com<issuer>
<scope>mail-w<scope>
<authURL>https://api.login.yahoo.com/oauth2/request_auth</authURL>
<tokenURL>https://api.login.yahoo.com/oauth2/get_token</tokenURL>
<oAuth2>
</pre>