Resolved Mail Name service error for one domain

[kmsys]

Hi,
I am really desperate about a problem which has occurred since I have transferred my plesk administered server to a new one:

For other domains ongoing mails are working but for one I get this error:


The mail system

<praxis@neurochirurgen.de>: Host or domain name not found. Name service error
for name=kmsys.de.neurochirurgen.detype=AAAA: Host not found

kmsys.de is the servername and neurochirurgen.de the domain where no mails can be delivered to.

I have checked the configuration of the domain‘s nameserver, but I don’t know why kmsys.de is set here in front of the domain neurochirurgen.de

Can you help me where I can search for the error?
I have also stated in main.cf that only ipv4 should be used and don’t understand it may still use ipv6 (type=AAAA)
You need more information?

 

[kmsys]

P.S.: Emails sent from another domain hosted on the server work, but not from external sources.

 

[IgorG]

Incorrect MX record specified in the domain DNS settings.
Note: Make sure that A record for this MX record hostname exists too. If DNS settings are not managed by Plesk, change it on the side of the DNS hosting provider or contact their support.

 

[kmsys]

Thank you! Solved! Removed an incorrect MX record on the name server.