From my experience shared web hosting accounts have the worst trust. You get the IP range of a public cloud provider, but you also share it with random people, that will send spam at some point.
So either get a package at some of those smaller providers with a dedicated IP, or go to one of the big providers (Google, Microsoft) and use their highly trusted IPs, that everybody whitelists by default.
So either get a package at some of those smaller providers with a dedicated IP, or go to one of the big providers (Google, Microsoft) and use their highly trusted IPs, that everybody whitelists by default.