RDNS PTR records check
To check is your ptr/rDNS records active you should simply run the next command in linux shell:
host -t PTR <ipaddress>
This command check the dns assignment :
host -a <hostname>
From Windows you can use nslookup
nslookup <ipaddress>
ALso you can use dig for MX records (and not only) check:
dig www.yourdomain.com
If you want to be sure that you check it directly, not from cache use dig + trace:
dig + trace www.yourdomain.com
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