need help fixing reverse DNS issue with Qmail please

[manarak]

Situation:
I run a Plesk 7.5.4 Server with Qmail installed.

Here is the problem:
Some e-mails sent from my server do not reach their recipients, the error is "helo failed" or "Reverse DNS lookup failed" or "host xy does not like (...)"

I searched the forum and read many posts about this, confirming that it is a reverse DNS problem. But none of the posts did a step-by-step explanation of how to fix the problem.

Can someone please help me to get rid of it?

 

[phoenixisp]

It appears that you have no PTR record for your server. Contact your ISP and ask them to create one for you.

 

[manarak]

My ISP just provides server housing as I have own DNS servers.
Is the PTR entry something I should do on the DNS servers or where should it be done?

 

[phoenixisp]

Where do you get your bandwidth? Your ISP. Unless you have a full block of IP addresses you probably do not have full control of your DNS, especially the reverse DNS. Even with a full block I had to make a special request to get my ISP to allow me full control of my DNS.

Running a search for reverse DNS a lot of threads have covered this. But this one is probably best

http://forum.plesk.com/showthread.p...perpage=10&highlight=reverse DNS&pagenumber=1

 

[manarak]

Thank you - I sent a request to my ISP.

But what should I have asked for, exactly?

A delegation for my couple of IPs or for a forward of PTR requests to my DNS servers?

 

[phoenixisp]

You should at least request a PTR record for your main server IP, the one that shared hosting is setup on. It should point to the hostname of your server (host.domain.com) If your ISP will allow you full control so much the better, as long as you know what you're doing with it.

 

[manarak]

Hello Phoenix

I have emailled back and forth several times with the hoster, I have the feeling that they do not know exactly what to do.

They offered to use my hostname for the PTR entry. Is that the right thing to do?
I think I didn't set the hostname, it is probably still localhost.

What I want to achieve is that users from the servers' 25 domains will be able to mail to AOL addresses for example.

 

[phoenixisp]

OK, we'll get this done. To see if you set a hostname, SSH in and do

#hostname

What comes up? If localhost, what do you want as your 'main' domain?

 

[manarak]

Thank you for helping me

hehe as I thought:

localhost.localdomain


OK, I did
# hostname server1.mydomain.com and set my hostname.

I edited etc/sysconfig/network
and set
hostname=server1.mydomain.com

did I forget something?
what now?

 

[manarak]

OK, I also changed the hostname in Plesk and the etc/hosts file.

 

[phoenixisp]

Now ask your ISP to create a PTR record for your shared IP pointing to your hostname.

Now, to become compliant with AOL you should also add a SPF text file to the main domain's DNS records. Learn about that here

http://www.openspf.org/dns.html

 

[manarak]

Thank you phoenix

Could you please give your last 2 cents as well:

I got 2 shared IPs for the same server, I take it that both PTR entries should point to the hostname?

And should the hostname be accessible through DNS (i.e. should the server be found when server1.mydomain.com is typed into the browser?)

I will look after that SPF too