Setup IMAP/SMTP auto configuration

We need an expert in email configuration to setup automatic configuration of IMAP and SMTP so that when a new email is configured on one of our domains, the end user just has to enter their email address and password and all the IMAP & SMTP settings are automatically pulled into the mail client. We have full control over our email servers (Postfix & Dovecot) and full control over the DNS for the domains. We can also setup a web server if that is required to serve the config information. This needs to work with as many email clients as possible, but as an absolute minimum it must work with Apple iOS, Apple MACOS (Mac Mail), Outlook 365 mail client, Windows mail and Thunderbird.