Adding a sending service or IP to your SPF in the platform, will not guarantee that email will pass DMARC with SPF for your domain.

That only takes care of half the problem, which is you whitelisting that service/IP for your domain. However, if those emails are not sent in SPF alignment for your domain, they will not pass DMARC.

Once you have added the respective service/IP on your domain's configuration in the platform, you will need to contact your service administrator (person/team in your organization that has set up that service to send emails on behalf of this domain) and let them know they will need to turn on SPF alignment in their admin console for your domain. That will enable those emails to be sent in SPF alignment for your domain and thus, pass DMARC with SPF.

If you added the sending service in your Enabled Senders list and the emails are still failing DMARC even though the emails are sent in SPF alignment for your domain, please contact the Valimail Support Team, so we can check and make sure the response for that sending service is up to date.

Related articles:

DMARC Alignment

DKIM and SPF alignment