Stock mail app not showing email body

I use the stock mail app to check a number of email accounts, including my Hotmail account (via IMAP). Until recently my email worked just fine but now when I read an email the body of the email doesn't load. I can see the from name and email and the subject, but I don't get the content of the email. As far as I'm aware I haven't changed anything. And other accounts load the complete email.