YouTrack as a Help Desk Follow

Hey everybody,

I try to use the Mail Integration as described here:
https://www.jetbrains.com/help/youtrack/standalone/7.0/Use-YouTrack-as-a-Help-Desk.html

Emails received in the INBOX but as soon as I try fetching them, I end up with the following error:

Failed to apply command "Last message related emails "$from" "$to" to issue created from email from "$from"

1. unknown command: Last message related emails "$from"

I did everything exactly as in the documentation ant checked it many times. Settings are given just like this.

If you guys have any ideas on the topic please let me know.
Thanks a lot!