Configuring DKIM Signing of e-mails
DKIM (DomainKeys Identified Mail) is one of existing ways to authenticate email messages. If the email contains a DKIM digital signature, the sender is set to high reliability.
This authentication is used to avoid the possibility of finding your server’s IP-address black listed on mail servers.
Run the following setup via the ISPmanager control panel for adding DKIM to your domain.
In ISPmanager, go to "Settings" -> "Features,” select "Mail Server..." and click the "Edit" button.
Check the "OpenDKIM (exim)" box and click on "Apply Changes."
Verify that the settings are in effect and emails now have a DKIM signature. Send an email from your email address to any external email inbox that you can access (your alternate e-mail). Check the "Inbox,” open the received email and review the headers. Make sure the “DKIM-Signature:” heading is among them; this is the DKIM signature.