Do you know who is running the email for that domain ?
I can probably look it up but if you already know that its easier for me to tell you what to do or who to contact
It looks like your email for that domain is being hosted by google
what you want to do is log into the google admin console for that domain at this page
if you can get in there you should be able to see if the address Harold is there and change the password ***** necessary so that you can get into it.
A more complicated issue would be if the domain email was switched to google recently. In that case your email and contacts etc would not have been switched to it and you would have to contact whoever had it previously and see if they still have it.