The first thing here is to disambiguate the "From Address", which unfortunately has two separate definitions
There is the 'envelope From' or 'smtp from' which is normally generated by CiviMail using the domain configured in Administer -> Civimail -> Mail Accounts. That "from" is not normally directly seen by the recipient, but is used for deliverability and bounce handling (and yes, can sometimes be seen by the recipient as well).
Then there is the 'header from' which is what the recipient sees and is less relevant in terms of deliverability (but still matters for different reasons), but also matters for optics and replies. That's the one you configure in the CiviMail From Addresses.
Until you specify what you're referring too, I'm concerned this issue will just generate confusion and misleading advice.
I think in your case, you want a system administrator to sort out the smtp-from issue and the deliverability. You should be able to put lots of different header-from addresses with different domains, but of course, it depends. Here's my more complicated long advice: