What steps to do to set the DNS PTR record, is the IP in reverse in the name needed?

Question

I had the following error:

<[email protected]>: host yyyyyyyyyyyy.yyyyyyyyyyyyy.de[33.33.33.33] refused to
    talk to me: yyyyyyyyyyyy.yyyyyyyyyyyyy.de (mxeue106) Nemesis ESMTP Service not
    available 554-No SMTP service 554 invalid DNS PTR resource record

Evidently I need to set the PTR records, in this forum thread invalid DNS PTR record.... I see that :

whilst the IP is backwards, the numbers themselves are not

So if i have an IP like 22.33.44.55 I supposedly need to have this add:

55.44.33.22.in-addr.arpa  300  IN  PTR  www.dummy_domain.com

Is .in-addr.arpa suffix mandatory?

Also I have IPs that are not managed by the my DNS provider can I add those too to my IP?

Thanks

_{Note: IP and names here are not reflecting reality, 22.33.44.55 and www.dummy_domain.com are not mine and [email protected], yyyyyyyyyyyy.yyyyyyyyyyyyy.de, 33.33.33.33 are changed}

Solution

If you define the zone as "44.33.22.in-addr.arpa." (notice the dot at the end) then you don't have to specify the whole suffix in the zone file, you can put it simply as "55 IN PTR reverse.dn.record.com." (notice the dot at the end). You can, however, also use the extended form of "55.44.33.22.in-addr.arpa. 300 IN PTR www.dummy_domain.com." (notice the dots after the FQDNs). As about the A record pointing back to the IP, it is not a requirement but most likely no software will validate your reverse DNS if the A record is not there as well.

EDIT:

You need to have the nameservers for that reverse zone delegated to your DNS server by the provider of your IP addresses.

You can setup reverse DNS to any name you want, just that, most likely, you will also need the A record to point back to your IP.