Automated IMAP Backup PowerShell Script

I need a dependable script that connects to my IONOS.com mailbox (I have full administrative access), walks through every IMAP folder, and saves each message as a separate .eml file inside a local directory tree that mirrors the mailbox structure exactly. Once the script is ready it should run unattended on a scheduled basis through Windows Task Scheduler. Prefer PowerShell script.

Preferred behavior
• Download all messages, keeping sub-folder hierarchy intact, to a folder named CURRENTDATE_EMAILADDRESS
• Produce clear logs and an exit status.

Deliverables
1. Source code with any required libraries or modules.
2. A brief README covering setup, credentials handling, and how to change paths or schedule frequency.
3. One test run that proves the folder structure and a sample of downloaded .eml files.