Hello,

is it posible to have multiple ptr records for single IP on public DNS or multiple PTR records for single IP may fail some SMTP compliance checks.

Any help would be appreciated.

Hi,

while most rDNS entries only have one PTR record, DNS does not restrict the number. However, having multiple PTR records for the same IP address is generally not recommended, unless there is a specific need.

Best regards

One reverse dns record matching your banner is fine. You dont have to have multiple ones even if you have multiple email domains. Think about how cloud filtering solutions like MessageLabs works.

Thank you for helping
The reason I asked the question is that I doubt some remote e-mail servers refuse communication to my exchange sever because of multiple ptr records pointing to single public IP address.I know if  ptr records is missing,some e-mail servers can refuse communication but I'm not sure if multiple ptr records can also prevent communication.
Therefore if I have 2 domains (e.g. abc.com & xyz.com) on my exchange server,I only need 1 ptr record  for my public IP address ?

Thank you for helping
The reason I asked the question is that I doubt some remote e-mail servers refuse communication to my exchange sever because of multiple ptr records pointing to single public IP address.I know if  ptr records is missing,some e-mail servers can refuse communication but I'm not sure if multiple ptr records can also prevent communication.
Therefore if I have 2 domains (e.g. abc.com & xyz.com) on my exchange server,I only need 1 ptr record  for my public IP address ?

Yes. You only need 1 PTR for each sending server that is resolvable on the internet.  The PTR check that some anti-spam solutions deply is simply to ensure that the sending server's IP has a reverse record in DNS that matches what the server is ad