Hello-
Our email security provider does not allow spoofing, and we have to specifically allow IP addresses. Zendesk's articles say to whitelist the servers listed in their SPF record. They have a TON of addresses! I don't want to open that big of a hole.
The question is this: are these IPs dedicated to Zendesk? Are there any shared services? For example, maybe Zendesk is using a larger provider, who is also used by other companies.
Thanks!
Dan