Apple unable to send email to a valid email address

I know this sounds unusual. I’ve had the Apple credit card for several years and added the card to my digital wallet on my iPhone and on my desktop Mac when I received the card. I’ve had about 33 transactions during the time I’ve had the card. About two months ago I received a paper statement instead of the usual email saying your statement is available by opening your digital wallet etc. I called Apple support and they told me the email they tried to send me bounced so they sent a paper statement.

My iPhone and desktop software are up to date. I’ve used the same email since I’ve had a Mac. Apple’s resolution was to change my Apple ID email, which I said I’ve used since I’ve owned a Mac (about 28 years) and don’t really want to change.

Anybody have any ideas?