Emails are very easily hacked, especially if they are common ones like Gmail, Yahoo, Hotmail, and etc, etc. So you shouldn't be surprised if you got hacked. Like SpiderVV said, you might just be a random person on this hacker's list, and that he wasn't really targeting you at all, but just want to hack your our of the thrill or the fun or even just experience of it.
It's good to have an alternate email, though this means that you will have to convince all your friends to use your new email and update them with the new information of your email being hacked. If you have a popular website and/or you are famous on the internet, especially if you own a blog, then you shouldn't be surprised if you are especially being targeted to get hacked. And if you are, then your webhost or your adsense (or whatever advertising company you use) might send in some crucial information and that account might get hacked too.
So if I was you, the first thing should be to check all of that and change the email to your new alternate address. Figuring out how to retrieve your email back comes second. I know that even Google Mail got hacked once, and it was targeting random visitors by only then visiting a specially set up site, and it only works for Google Mail. They insert a filter through into your email account (only if you are already logged into Google Mail), and you won't notice a thing because emails containing certain words will get sent to another email address (the hacker's) and then after that, it will get deleted automatically, and you won't notice anything. If you want to stop this hack, you will have to go to "Filters" in the Settings area and delete the filter that was automatically put there. So, as I said, it is pretty easy to get hacked...
But not so easy as to retrieving your email back, especially if the password is changed... so about that...
But in your case, I mean, if a random email pops out, then I would just think that it was junk mail. I mean... well, the hacker didn't really access your email account with your password, did they? I personally think that it is just junk mail.
And no, I haven't seen the email address before... but changing your password is a good precaution. You should do that often, and password hacks can take an incredibly unbelievable long time, so if you change then periodically, you should have nothing to worry about.