Sudden realization that one of my American banks must be having email problems with this too because I use a Google custom email and recently got an in-app notification from my bank saying "we're unable to email you" (and a letter) yet my email works perfectly fine... switching to consumer gmail worked.
Do you actually not receive their emails? Fidelity uses tracker dots to check email receipt, which drives me nuts, because like any sane person I don't allow emails to load images without damn good reason. My brokerage should not be sending me cute dog photos, thus I have no need of their images.
So they send me an email, send me another email saying they can't reach me by email, then mail me a letter with the same content as the original letter, and mail me an additional letter saying they can't reach me by email.
For some reason the announcement they sent me didn't show up in my email, which was odd. I've had other bank notifications come through unopened before, even after that announcement.