I found this "email address checker" this week (I think on how-to geek.com web site.)
What I have is a non-downloaded free tool which lets you check any suspicious email address one at a time, which for me is fine. You keep the bookmark and if you find a fishy address,you write it on the page which this link provides.
There is a paid version for corp. or such,this one at a time freebie is great formyself!