Issue Catch-All adds Catch-All Mailxbox as recipient

[dennis_81]

Hello,

we are using catch-all function for a domain in Plesk. I have defined that mails to unknown recipients are forwarded to the catch-all mailbox catchall@domain.com.
The mailbox catchall@domain.com is fetched by a Pop3 Connector (PopCon) and mails are delivered to Exchange.
Now I have the following problem:
The PopConnector recognizes not only the original recipient, e.g. user1@domain.com but also catchall@domain.com as a recipient and so delivers every mail to the postmaster, too.

Mail header looks like this:

X-Original-To: catchall@domain.com
Delivered-To: catchall@domain.com
Received: from plesk01.domain.com (localhost.localdomain [127.0.0.1])
    by plesk01.domain.com (Postfix) with ESMTP id 7C0912810E3
    for <catchall@domain.com>; Tue,  8 Feb 2022 10:43:20 +0100 (CET)
...
Received: from mail01.domain.com (mail01.domain.com [1.2.3.4])
    by plesk01.domain.com (Postfix) with ESMTPS id 76361480A69
    for <user1@domain.com>; Tue,  8 Feb 2022 10:43:19 +0100 (CET)

If I disable the processing of "X-Original-To:", "Delivered-To:" and "for" in PopCon, the mails are delivered correctly, but BCC mails are no longer delivered.

How can I prevent Plesk from defining the catch-all mailbox as an additional recipient in each mail? We did not have this problem with our old mail server.




Thanks for your help

Best regards
Dennis