Based on https://www.murat.ws/openfire-iredmail-yapilandirmasi/, we are able to integrate iRedMail 0.97 to openfire 4.0.3. I know the document is in Turkish but focus on the script statements and SQL commands. Replace jdbcProvider.connectionString', 'jdbc:mysql://localhost:3306/vmail?user=kullanici&password=sifreniz' - with iRedMail.tips vmail and the password.

The trick is once you moved the authentication to vmail database, create an account admin@example.com with the proper password. With that then you can login to http://www.example.com:9090 and login with the credential admin (stored in vmail). Although credential stored in vmail is admin@example.com, the last line in the above documentation is jdbcUserProvider.usernameField', 'local_part' - so it would take the local_part which is admin and allow you to login.

But we are having problems to do openfire 4.2.1, we are trying, but let see what we can get in the next few days.

Related to this is the possibility of using iRedMail Pro REST API to do development work. Openfire has a very nice web admin interface as compare to Prosdy-0.10. By doing the authentication through custom database (vmail), we will lose a lot of useful information such as session, transaction info, we are new to REST API, just wonder that is a good idea to develop application to work with openfire.

For those who are in need of adding XMPP with iRedMail, Zhang had actually helped me in doing it. We are testing it now