unable send email type=A: Host found but no data

I guess that was after upgrading Virtualmin to 3.69, the postfix stopped to send emails
The error displayed is:

<some_address@bol.com.br>: Host or domain name not found. Name service
error for name=bol.com.br type=A: Host found but no data record of
requested type

The machine is a Debian 4.0 Etch running inside a Virtuozzo VPS. So, it is possbile that the hosting company altered something else. I discovered that /etc/resolv.conf was rewritten by them, changed nameserves and removed I included it again, but it did not solve the problem.
Rechecked configuration using the virtualmin menu. It shows all ok.
Before, at 3.68, I used the hint at
and it worked, but not now anymore.
What could I do?
Andre Felipe Machado

My guess is that there’s something wrong with the DNS server that it’s using to perform the query for that domain name.

It may have cached a bad value for that domain name, amongst other possible issues.

One way of resolving that might be to remove the entries from /etc/resolv.conf except for – and then restart BIND.

Thanks a lot for your hint.
This pointed to the actual solution:
The hosting provider changed the resolv.conf /etc/hostname and /etc/hosts (automatically?) AND changed its name servers infrastructure after the files edition.
So, after asking them about for the new valid nameservers, I configured again /etc/resolv.conf and postfix is sending emails again.
Andre Felipe Machado