Only allow email from domain "x.y.z" from specifc IP's

[Budi F]

Hi,
We uses MailScanner version 5.3.3, CentOS release 7.8.2003 and
Postfix-2.10.1-9.

We have another domain, called "x.y.z"  which is our sister company.
Right now we put domain "x.y.z" into our whitelist, but it become a
problem when we received many spoof emails claim from domain "x.y.z"

Is it possible that we only allow email from domain "x.y.z" only from a
specific IP address, and reject the rest?

We can use SPF but that means we need to exclude domain "x.y.z" from our
whitelist.

Or if there any other way that we can receive only the valid email from
domain "x.y.z" ?

TIA

Regards
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