Dokku droplet and email forwarding to specific email address
I hosted my website to a dokku droplet yesterday using the digitalocean nameservers and my own domain (works fine). Now my custom email address email@example.com does'nt work anymore because my registrar (checkdomain.de) does not support email forwarding when I use another nameserver.
Question: How can I forward emails from firstname.lastname@example.org to another email address (not gmail)? I don't understand how to set an MX record that points to a specific email address.