When emails are sent and not delivered (returned to us for any reason) we suspend further emails. I have reset this for you, so emails should once again be delivered.
For anyone else experiencing this in the future :
To check if this is the case for you too, visit your "My Home" page where you will be warned of this situation and get an option to restart email sending to your email account.
Why does this happen? To protect RHPs reputation as a mass sender of emails (and not classified as a spammer) we need to make sure emails are not sent to addresses that refuse our email.