rDNS error

[chieflorenzo]

Hi, I'm getting an error on one of my clients' accounts that seems to only show up when they send email. Many messages are bouncing back, and one of them recently had a clue in it:

421 DNS:NR

* The Reverse DNS lookup for your IP address is failing. This could be a transient issue. Confirm the IP that sends your mail. Then check the rDNS of that IP using our troubleshooting tools. If it passes, please wait 24 hours and re-try before opening a support request.
o rDNS must be in the form of a fully-qualified domain name. rDNS containing in-addr.arpa are not acceptable, as these are merely placeholders for a valid PTR record. rDNS consisting of IP addresses are also not acceptable, as they do not correctly establish the relationship between domain and IP address.
o rDNS that may be similar to dynamic IP space (containing pool, dhcp, dyn, etc.) may be treated as suspect, and should therefore should be changed to reflect a fully-qualified domain name with standard reverse DNS.

This was returned from an aol email address, but other bounces have referred to PTR records. The domain is fossilfestival.com

What do I need to do?

Thanks very much

[Rock]

Hi Laurence,


A PTR record is the reverse of an A record. That is, it maps an IP address to a hostname, rather than vice versa. Given an IP address of the form a.b.c.d, the usual form for a PTR record is this:

<code>d.c.b.a.in-addr.arpa. PTR host.name.</code>

Having a PTR record is most commonly used security policy today which is followed by well know email providers like AOL, Hotmail, Yahoo, gMail, BT & many more. If your client is not able to send mails to our server then it confirmed that he/she is not able to send on any account with above providers.

Most of the mail servers check whether there is a rDNS set for the IP from where the email is coming from & if there is no rDNS record set, it rejects the email considering it as spam. This is the reason why most of the people now a days set rDNS record for the main IP of the server (generally to the hostname of the server) as by default emails are routed out from the main IP of the server.

Hence, we've setup the PTR record to the hostname of your VPS, so that all the domains hosted on it won't face issues with PTR records..

Please check if your emails are still bouncing back due to PTR/rDNS issues. Standing by to assist...

[Rsync]

Hi, I'm getting an error on one of my clients' accounts that seems to only show up when they send email. Many messages are bouncing back, and one of them recently had a clue in it:

421 DNS:NR

* The Reverse DNS lookup for your IP address is failing. This could be a transient issue. Confirm the IP that sends your mail. Then check the rDNS of that IP using our troubleshooting tools. If it passes, please wait 24 hours and re-try before opening a support request.
o rDNS must be in the form of a fully-qualified domain name. rDNS containing in-addr.arpa are not acceptable, as these are merely placeholders for a valid PTR record. rDNS consisting of IP addresses are also not acceptable, as they do not correctly establish the relationship between domain and IP address.
o rDNS that may be similar to dynamic IP space (containing pool, dhcp, dyn, etc.) may be treated as suspect, and should therefore should be changed to reflect a fully-qualified domain name with standard reverse DNS.

This was returned from an aol email address, but other bounces have referred to PTR records. The domain is fossilfestival.com

What do I need to do?

Thanks very much

Hello,

Reverse DNS resolution (rDNS) is the determination of a domain name that is associated with a given IP address using the Domain Name System (DNS) of the Internet.

rDNS record for your VPS server IP didn't exist, due to which emails were being bounced back from AOL. We have added the rDNS entry pointing it to your VPS hostname, it will take some time for the DNS propagation all over the internet. Once propagation completes, email will start working to AOL or to any mail provide which prefer rDNS without any further problems..

[chieflorenzo]

many thanks for your help. appears to have sorted it

[eUK-Alan]

Hello

Glad to know that issue has been resolved