Misschien kan deze instructie ooit behulpzaam zijn:
https://serverfault.com/questions/1082302/create-a-dkim-key-to-provide-to-a-3rd-party-so-we-can-send-as-them
Of eventueel deze info:
https://www.reddit.com/r/sysadmin/comments/yexanx/how_can_i_align_spf_dkim_and_dmarc_so_that_third/
https://serverfault.com/questions/1082302/create-a-dkim-key-to-provide-to-a-3rd-party-so-we-can-send-as-them
Of eventueel deze info:
https://www.reddit.com/r/sysadmin/comments/yexanx/how_can_i_align_spf_dkim_and_dmarc_so_that_third/