ну блин упертый

nslookup -type=mx amazon.com
amazon.com mail exchanger = 5 amazon-smtp.amazon.com.

host amazon-smtp.amazon.com
amazon-smtp.amazon.com has address 207.171.188.9
amazon-smtp.amazon.com has address 52.94.124.7
amazon-smtp.amazon.com has address 207.171.188.200
amazon-smtp.amazon.com has address 207.171.188.180
amazon-smtp.amazon.com has address 52.119.213.150
amazon-smtp.amazon.com has address 207.171.188.4

host 207.171.188.9
9.188.171.207.in-addr.arpa domain name pointer smtp-fw-0102.amazon.com.

и что теперь почту не принимать так как реверс кривой?
при этом

amazon.com. 60 IN TXT "v=spf1 include:spf1.amazon.com include:spf2.amazon.com include:amazonses.com -all"
amazon.com. 60 IN TXT "spf2.0/pra include:spf1.amazon.com include:spf2.amazon.com include:amazonses.com -all"

тут вам не гугл... амазон сам говорит, что все что не влезло в паттерн, слать нахер ибо '-all'