Greenhouse is capable of sending DMARC compliant email because they support custom SPF and DKIM configurations that achieve DMARC alignment. Greenhouse is an Employee Recruitment Platform and is often used by Human Resource teams.
The link just below is a resource on how to configure this source to send DKIM-aligned email on your behalf. You will complete this configuration by (1) following the source's instructions and (2) adding the required entries into your DNS. https://support.greenhouse.io/hc/en-us/articles/201111684-Email-Verification
The link just below is a resource on how to configure this source to send SPF-aligned email on your behalf. You will complete this configuration by (1) following the source's instructions and (2) adding the required entries into your DNS. https://support.greenhouse.io/hc/en-us/articles/201111684-Email-Verification