Our data indicates AcquireTM supports DMARC compliance via SPF.
Contact AcquireTM to ask about their DKIM capabilities.
All data we've noticed seems to come from 'mail.acquiretm.com', which for the time being translates to an addition of 'ip4:54.70.98.207' to your SPF. In any case, be sure to contact AcquireTM and verify this information.