SPF will pass if there is no SPF record in the domain. Which most probably is the case for most. Look for DKIM. Either it's signed and pass. Or spam if DKIM is

SPF will pass if there is no SPF record in the domain. Which most probably is the case for most. Look for DKIM. Either it's signed and pass. Or spam if DKIM is missing. You can filter a lot more this way.