It happened to me too! Isn't it annoying?
I received a job offer in a field I had absolutely no qualifications for.
I always wondered what would have happened if I had accepted it.
And I even received a very long and romantic love letter!
At this point I was so annoyed, I asked my boyfriend to reply. He simply said "I think you have the wrong email address... otherwise... do not touch my girlfriend"
I also get emails for this woman with the same name as me who is active in the anti-abortion movement.
They get my email address from my webpage (I am a researcher and I need one to put my publications, research interests and contact information for my colleagues) and automatically assume we must be the same person.
I finally decided to put a note saying I am not this person and do not want to be contacted about these issues. It's been working for now...
I must say, the husband thing is ridiculous.
A mistake can happen once in a while, but obviously you are receiving many. Since you have the husband's email, I would write him and say that from now on you will simply delete these emails.
I wouldn't feel too bad about it.