Mail Server Error

I am trying to add a mailbox, but I received this error..

Hello, is it normal to try to add the mail server in the app store?

Well, where should I add it?

Adrian

Adrian
Check whether the MX record resolution of the domain name points to the server's IP?
You can also refer to this post
https://www.aapanel.com/forum/d/16417-issue-with-a-record-and-mail-server
cat /www/server/panel/data/iplist.txt

Yes, thank you, solved!

And can you please delete my latest photo?

yes