Neither Google or Microsoft use long term IP reputation. They may temporarily block an IP for various reasons (it will even reflect that in the SMTP error message), but never in the long term. All major email service providers work with domain reputation, not IP reputation.
However, you do need proof that you 'own' the IP address by means of a reverse IP address. ISPs generally don't allow their customers to set a reverse-DNS record for the IP address, because you do not own the IP. Since most spam originates from botnets from consumer IP addresses, adding the reverse-DNS requirement resulted in a huge reduction in spam.
The email service providers didn't ruin email, spammers did.
However, you do need proof that you 'own' the IP address by means of a reverse IP address. ISPs generally don't allow their customers to set a reverse-DNS record for the IP address, because you do not own the IP. Since most spam originates from botnets from consumer IP addresses, adding the reverse-DNS requirement resulted in a huge reduction in spam.
The email service providers didn't ruin email, spammers did.