Resolved re: issues sending e-mail from server to one specific domain!

[zoldos]

Hi, I'm having problems sending e-mails from my Ubunto 16.04/Plesk 17.05 server to one specific domain, "gmx.net". Below is what they reported as the issue. How do I fix this? Thanks!

- no domain name is assigned to your server's IP in the DNS (domain name system)
- your DNS Records point to a list of dynamic IP addresses or to your provider's default entries
- the DNS record that you are using is not accepted by us.

In order to be able to deliver emails to our system, please ensure that your server has a valid domain name (Fully Qualified Domain Name - FQDN) and a reverse lookup (rDNS).

We would also advise you to choose a name that it is different from the default entry of your provider, like "123-123-123-123-static.provider.tld".

A good format would be, for example: "mail.yourdomain.tld".

 

[IgorG]

First of all make sure that hostname of your mailserver is resolvable to correct IP address.

 

[zoldos]

First of all make sure that hostname of your mailserver is resolvable to correct IP address.

Thanks! Can you please tell me how to check this? I've never had this error before, and I can send mail to any other domain...

 

[Rob Taylor]

You can just use the 'dig' command... so to check your hostname resolves correctly just login to a command line on any machine / computer and run:

dig <your-server-hostname>

....the result should match your server hostname.

You should then check the reverse DNS lookup so if you then run the following command:

dig -x <your-server-ip>

...the result should be your server hostname.

If these two don't match up it can cause email deliverability issues so you would need to fix.

Thanks
Rob

 

[zoldos]

Thanks! I checked, and they match up perfectly. I also added another "include:" statement to my DNS spf record with the full hostname, and I've verified and checked all other DNS records. Hmm....I'm not sure what else it could be....

 

[Rob Taylor]

Okay - I have just sent a test message to [email protected] from one of my Plesk servers and it did not return that error so does seem to be something specific to your server.

If you want to PM me your server hostname, IP and sender domain I can have a quick look for you to see if I can see any issues with the DNS config...?

Alternatively, you could try running a domain health tool on your server hostname and sender domain to see if that highlights any problems, I would recommend MXToolbox:

Domain Health Check - Online Domain Tools - Blacklist, Email, Website, DNS - MxToolBox

Thanks
Rob

 

[zoldos]

PM sent.

 

[Bitpalast]

How do I fix this?

Most likely the PTR record is missing for your host name. It is required for reverse name resolution rDNS. Your provider must set it so that the IP address of your server will be resolved to it's name.

 

[zoldos]

Most likely the PTR record is missing for your host name. It is required for reverse name resolution rDNS. Your provider must set it so that the IP address of your server will be resolved to it's name.

I'm pretty sure that is all already set up. The reverse DNS is pointed correctly. If this is the reason tho, why would I my server be able to send to *anyone*, except a single domain? Or would that not make a difference?

 

[Rob Taylor]

I have replied to your PM, would fix up your SPF first to see if that resolves the issue.

Thanks
Rob