[Exim] What does DNS try to resolve when encounter error: "S…

    Thanks for any helps in advance.
    Our users received "Sender domain must exist" kind of bounce back emails on
certain recipient SMTP servers.
    We have added the A record for the domain, e.g. mybiz.net, into our DNS server
and still failed. I wonder what does MTA asking the DNS to resolve for it?
    dig domain A? dig domain MX? dig mx A?
    And if our SMTP server has different IP from the domain's IP, does it matter?
    'Coz   "dig mybiz.net MX" will get "smtp.hitech.com.my".
    Thanks.

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Simon Tneoh Chee-Boon simon.tneoh@???
Senior Technologist MyBiz International Limited
Tel: (60)3-2713-8181    Fax: (60)3-2713-8811
Personal: http://www.tneoh.zoneit.com/simon/
Company:  http://www.mybiz.net