Would you mind sharing where you host your email server? I have a pet theory that big email platforms care deeply about the IP "neighborhood" the sending email

Would you mind sharing where you host your email server? I have a pet theory that big email platforms care deeply about the IP "neighborhood" the sending email server lives in. So a small email server set up perfectly in Digital Ocean IP space would struggle, while an email server set up OK in (for example) CenturyLink Enterprise IP space would get through.