If DKIM is enabled, every form and newsletter on the website will no longer be sent using the email address entered individually in the content, but rather using the centrally stored DKIM address. This has the advantage that the emails usually arrive safely at the recipient and do not end up in the spam folder.
The sender address entered individually in the form or newsletter will still appear in the recipient's inbox, but not as the sender address, but as the reply-to address.
DKIM must be activated by the Internet administration. A DKIM sender address is stored centrally. This centrally stored DKIM sender address can also be customized individually by the Internet administration for different (sub)sites.