On 6/18/20 5:46 PM, Michael Peddemors via mailop wrote:
On 2020-06-18 4:37 a.m., Benoît Panizzon via mailop wrote:Allow your customers to set an additional PTR.AFAIK only one PTR per RR is allowed, even if most DNS allow to set multiple ones.And when you say 'only one PTR per RR' is "allowed", could you explain that further? "allowed" by whom, or what policy.Multiple PTR's do have a legitimate reason sometimes, albeit nothing worse than the operator who has 40-50 PTR records, this is not efficient, for DNS queries..DNS Round Robin is still a common thing, where systems may share a name in the PTR's but also have a unique name..Other reasons for multiple PTR's still do exist, eg transitioning from one naming convention to another, so systems should be designed to 'walk' the PTR records, and 'A' records, when doing 'match' validation.
Just because checking for a valid FCrDNS is quite common nowadays and some mail software may fail at that if there are multiple PTR.
That said, having to set the RDNS to something in the domain of the customer is the most stupid requirement I have ever seen. And that will fail with all outlook based mail domains for example anyway.
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