You can. I might be able to (there’s a lot of crap around spam filtering and SPF that I’d have to fight with).
My mother, father, sister, cousins, nieces and nephews? Not a chance in hell.
We have an admin who spends a good 40% of his workweek doing just our email servers. They are a massive PITA.
Meanwhile, I'll be pushing my representative for regulatory action.
...until your upstream changes something.