Resolved Can't receive email - DNS Error

[PeterH]

Server operating system version

Ubuntu 22.04

Plesk version and microupdate number

18.0.58 Update #2

I don't receive any mail in roundcube. Sending email does not cause any problems, but receiving does.

I created the email address info@example.com. If I send an email with this email address to, say, user@gmail.com, user@gmail.com will receive it in his mail box. I don't receive an email when he answers my email. In fact, I don't receive any emails at all.

A few hours after user@gmail.com replied to my email, he received an email from Google with the following message:

DNS Error: DNS type 'mx' lookup of example.com responded with code NOERROR DNS type 'aaaa' lookup of mail. responded with code NXDOMAIN DNS type 'a' lookup of mail. responded with code NXDOMAIN

I'm still a beginner when it comes to Linux, Ubuntu and Plesk so it would be great if someone could explain to me what exactly this message means.

Thank you

 

[Peter Debik]

Does your domain have an MX record and does that record point to your server?

 

[PeterH]

Good morning, thank you for your response.

I've attached two images so you can see how I set up the MX record and an A record pointing to my server's IP address.

My domain uses the name servers of the domain registrar while my server uses the name servers of my hosting provider. They are two separate parties. Could this be the cause?

 

[PeterH]

Forgot to mention that I disabled IPv6 addresses on the server

 

[Peter Debik]

I think the "example.com" in the first line is wrong, because that will result in "example.com.example.com". Instead, i should either be left blank or a placeholder like "@" is required to represent the domain in itself. Other entries will be seen as a subdomain. Hence the real MX record for the domain cannot be found which leads to the symptoms described above.

 

[PeterH]

I cannot select the "@" and if I leave out example.com it will be there again after saving the changes. So I have now set the MX record as in the image below, but I fear that this will not work. I removed the "A" record as above in the second image.

 

[Peter Debik]

Did you ask your domain provider what to fill in?

 

[PeterH]

I have a number of domains with the same provider and they also have the same problem. I have moved the domain names to another provider and hopefully I will not have any more problems once the transfers are complete. I'll keep you informed. So far thank you for your support.

 

[PeterH]

My apologies for the late response, but the problem has been resolved and I can now receive emails. Thank you for your support.