Hi @kwbc2020,
I’ve check the DKIM record for your domain kernwheelmen.org and I see it’s not properly set up.
Some DNS providers may create DNS records with a duplicate the domain name, causing “mailpoet1._domainkey.example.com” record to be incorrectly created as “mailpoet1._domainkey.example.com.example.com”. This is the case here, as I could find a DKIM record kernwheelmen.org.kernwheelmen.org:mailpoet1
To fix this, please try removing the domain name from the record’s name, leaving it as ” mailpoet1._domainkey”, “mailpoet2._domainkey” and “_mailpoet”.
Thanks!