Richy, it sounds like your e-mail has been hacked. When this happened to me a few years back, everyone in my inbox were getting e-mails from me trying to flog them Viagra; and I've got both Buddhists (including a monk) and Christians (including a priest) in my e-mail addresses. Made me smile.
I was told I should change my password, which I did, but then forgot it, couldn't get back into my e-mail account, so had to create another one, which was annoying.
Try changing your password.