Auto responder does not work correctly. It replies to messages with
"Precedence: list" and presumable
"Precedence: bulk", which is not the expected result.
If activate auto responder for email account through Plesk and then send email to this account from mailing list, autoresponder will ignore header
"Precedence: list" send autoreply to whole maillist.
At the same time auto responder does not send replies to messages with
"Precedence: bulk" header.
Such behavior is known as software issue #PPPM-3321.
The issue will be fixed in further updates of the product.