PTR Record

Hosting to provide as standard?

[limbo]

Should a host offer reverse DNS and a PTR record as standard?

We have recently moved hosts but our new one does not support this - so as a result mail from some ISP's is being bounced with this error:

Your message did not reach some or all of the intended recipients.

Subject: test e-mail

Sent: 20/03/2006 10:30

The following recipient(s) could not be reached:

'[e-mail]' on 20/03/2006 10:30

There was a SMTP communication problem with the recipient's email server. Please contact your system administrator.

<sitename2000.sitename.demon.co.uk #5.5.0 smtp;550 relay not permitted>

A little digging turned this up

No PTR records exist for (our IP address) [Neg TTL=3600 seconds]

Details:
ns.hostnameserver.tld. (an authoritative nameserver for (their IP address).in-addr.arpa., which is in charge of the reverse DNS for (our IP address))
says that there are no PTR records for (our IP address).

To get reverse DNS set up for (ip address), you need to speak to your Internet provider. You could also
check with [e-mail]., who is in charge of the (their IP address).in-addr.arpa. zone.

Note that all Internet accessible hosts are expected to have a reverse DNS entry (per RFC1912 2.1),
and many mailservers (such as AOL) will likely block E-mail from mailservers with no reverse DNS entry.

Can anyone make sense of this? Designers make lowsy IT guys...

Cheers, Limbo.

[Mr_Fern]

A PTR Record is designed for Reverse DNS. Although it's usefulness is greater for dedicated servers as opposed to those used for shared hosting.

Every computer has a hostname xyz.somedomain.tld
A PTR Record works in the following way:

If the IP to your machine is 1.2.3.4, then your PTR record is 4.3.2.1.in-addr.arpa

4.3.2.1.in-addr.arpa IN PTR xyz.somedomain.tld

So when they do a reverse DNS, they look at this PTR record to get the hostname for that particular IP.

To answer your question, yes it should be standard. Like the dns report.com report gave you, many e-mail carriers will reject mail if they can't do a host lookup on the IP sending mail. If they're missing, either the DNS server handling Reverse Lookups for your host was down during a lookup, or they just don't have them. You should contact the host about this.

[limbo]

Thanks Mr Fern (had a school teacher named that who made a lot less sense ;))

Will make some more enquiries

Cheers

Limbo