I have the following problem with the SMTP and DNS.
I have two domains configured. Domain A.cz and B.cz. In the domain B.cz
there is an A RR (isp.B.cz) and appropriate MX RR (isp.B.cz) for this
machine. In the domain A.cz there is a CNAME RR pointing to the A RR in
the B.cz domain (ms.A.cz->isp.B.cz). Now when I want to send an email to
the machine ms.A.cz (test@ms.A.cz), SMTP servers translate To: field in
the email from the CNAME to the A RR and the result is that I can't send
an email to that host because it says that it is not responsible for
email test@isp.B.cz. But I originally wanted to send an email to the
account test@ms.A.cz. Could anyone explain me, why SMTP servers
translate the fields in the emails?