Our data indicates TransIP supports full DMARC compliance.
Contact support for DKIM setup.
You could add 'include:_spf.transip.email' to your SPF but beware that pulls in additional DNS-querying mechanisms. Contact TransIP for a better authorization, if possible and visit the following page for more information: https://www.transip.eu/knowledgebase/entry/426-setting-an-spf-record/