There is a ten lookup limit for SPF records. To get around this some companies are offering to host your SPF record on their server and replace the "includes" with the actual IP addresses of the remote email servers. This "flattens" the SPF record and gets around the ten lookup limit. The service frequently checks for updates to the includes and keeps the addresses updated. Has anybody ever used one of these services? I'm leery about having another company host any DNS record on my behalf. Also wondering if Infoblox would consider adding an SPF flattening feature to NIOS to get around the ten lookup limit.
I realize there are other ways to get around the ten lookup limit by placing third party mailers in a sub-domain. In large organizations it can be difficult to restructure the domains after the fact.
