How do I add the GetResponse IP addresses to a whitelist (advance-authorized list of email addresses, held by an ISP) in our domain. Our emails are ending up in spam - even my own email address rejects my own company emails. GetResponse says, “(FROM and TO addresses were the same) but with our IPs in the middle. This can often cause false-positive spam/spoofing alerts because receiving servers expect different sending IPs.”
Your question appears in the #general:email-routing category, which refers to a specific Cloudflare product that provides forwarding for domain emails to third-party mailboxes. Your question sounds like you need assistance with email authentication, which is something that falls outside of the topics supported by the Cloudflare community.
You make mention of a whitelist, but that is something that can only be implemented by the administrator of the receiving mailserver. I can tell you that with twenty five years as a mailserver admin, granting wholesale pre-approval to an email marketing company’s IP ranges is likely to be given serious consideration around two years after the heat death of the universe.
What you most likely need is to configure your Get Response account to use valid SPF and DKIM for your domain. I found an article on configuring Get Response DKIM. They are reported to support SPF, too, but I don’t see the relevant article in their knowledge base. You may need to ask their support for details.