Record contains too many lookups (SPF Records)

DougBartley got ya, it's my fault for not reading your full reply. However, in this scenario the 10 DNS lookups limit still applies, and it's actually magnified by the additional includes you've added. The only benefits you get are for adding large number of IP blocks. For example, none of those 3 separate records exhausts the 10 lookups, but when you combine them together, you invalidate the record:

v=spf1 include:spf.protection.outlook.com include:_spf.google.com include:amazon.com -all

Jeff Harlow why wouldn't they, all you need to do is tell the vendor that you want those messages being sent from say user@marketing.domain.com instead of user@domain.com.