Issue Change DKIM Signature mail headers

[vargasia]

Server operating system version

Debian 12

Plesk version and microupdate number

18.0.71 #4

Hi there.

I noticed an issue with the DKIM signature Plesk generates.

The DKIM-Signature header includes this:
h=Received:Received:From:To:Subject;

Two problems here:

1. The Received header is repeated twice.
2. Important headers like Date, Message-ID, and MIME-Version are completely missing from the signed headers list.

This weakens the DKIM signature and causes Hotmail/Outlook to reject or mark the DKIM as invalid, even though other providers accept it fine.

I suspect Plesk’s DKIM signing component is not properly configuring which headers to sign, or there’s a bug causing header duplication and omission.

Can someone confirm this is a known issue? Is there a fix or a way to customize which headers get signed in Plesk’s DKIM?

Thanks in advance.