If you have a @mac.com address, the @me.com and @icloud.com addresses are automatically yours. The breakdown lies with the person who thinks your @icloud.com address is his email address.
Yeah, I’ve got one of these early gmail addresses which I rarely use anymore. I once got a legal contract for review by someone who gushed about how it’s great to have a sister for a lawyer… Right. As a general rule I mark these as spam hoping not to see them again, though I did finally send an email to a relative of that lawyer to tell them they had the wrong address when I started getting emails from her old mother… Most of the emails intended to other people were not personal.
Speaking of personal, one of these namesakes had used my email as her “alternate” email for her Yahoo account, and they sent me a notification about that… I ended up signing into her account – I said I forgot my password and they sent me a code to the secondary email to log on/change my password… easy-peasy, and a bit scary. I didn’t snoop or anything, just deleted the “alternate email” … I figured she’d just change her password the next time in the same way.
I gotta say, I’ve been at the other end of the stick at least once that I’m aware-- sending an email to my husband’s last name and first initial, and forgetting to add the numbers that are part of his email address… That email of course never bounced, I just realized my mistake the second I hit send… (duh)
All this makes me really happy that I registered a vanity domain (email hosted by gmail) email@example.com which is almost unique in the world: there’s one other firstname lastname. Occasionally I’ve been asked whether I’m him, but I never got any of his emails.
However, it also happened that my wife’s iMessage’s didn’t end up with me, but with someone else.
Regarding your wife’s iMessages – make sure that her entry for you in her address book has the correct email address. It’s more likely that there’s a typo there, than a single iCloud address going to different people.
I generally redirect or return misdirected non-promotional email as a matter of courtesy if it’s from someone trying to find another Jeff Hecht. Sometimes they come at odd times. The most recent one was an estimate for installation of a $50,000 rooftop solar cell array that came in when we’re looking for a Heat Pump HVAC system.