I have one personal domain at Fastmail that I use nearly always, but it’s a .me domain and I’ve ran into weird issues with certain services thinking it’s a fake

I have one personal domain at Fastmail that I use nearly always, but it’s a .me domain and I’ve ran into weird issues with certain services thinking it’s a fake email address or just general unexplained delivery issues over the years, so I fall back to a fastmail.com address in those cases. I also have iCloud and GMail addresses I rarely ever use. I forward everything into Fastmail and use their web interface and mobile apps. I have a work address I keep entirely separate.