How to set up Plesk, mail autodiscover and Cloudflare to work together properly manually?

Question

• How to make Plesk, mail autodiscover and Cloudflare work correctly?
• How to set up Plesk, mail autodiscover and Cloudflare to work together for a domain?
• How to configure Plesk, mail autodiscover and Cloudflare to work together for a website?

Answer

The end goal of the setup provided below is to leave mail.example.com in the DNS Only status on the side of Cloudflare and set up mail autodiscover on the side of Plesk to use mail.example.com as the Incoming and Outgoing mail server to be autodiscovered by mail clients.

Warning: These setup steps are entirely manual and should be executed only while the DNS Integration for Cloudflare® extension is not installed or used on the Plesk server

In order to set up Cloudflare to work with mail autodiscover and websites hosted on a Plesk server, you must follow these steps:

1. A Wildcard Let's Encrypt SSL certificate (or a Wildcard SSL from a different SSL vendor) must be issued and installed for example.com and the hostname of the server (server.example.com) on the side of Plesk

Note: SSL certificates issued by Cloudflare do not have the ability to secure mail server connections on SMTP, POP3 and IMAP ports, due to which they cannot be used to secure email transactions.

2. The domain should be <a style="--link-color: #75b6ea !important;--link-color-hover: #90c4ee !important;--link-color-active: #71b3ea !important;--visited-color: #a075ea !important;--visited-color-hover: #b390ee !important;--visited-color-active: #9d71ea !important;--original-color: #000000" href="https://docs.plesk.com/en-US/obsidian/customer-guide/websites-and-domains/securing-connections-with…