I’ve just moved one web site over to CF, and let DNS wizard find all matching records. Nothing special was there, few classic A-records, MX and SPF record.
Looking at MX section, there is in DNS tab of CloudFlare:
MX domain.com domain.com AUTO DNS Only
But if I query one of CloudFlare DNS servers, they return weird record:
domain.com. 300 IN MX 0 dc-e1aeaff24449.domain.com.
What the heck?