E-mail system failure

Until yesterday morning, I was able to send and receive e-mails using *** Email address is removed for privacy *** which uses a hotmail account (*** Email address is removed for privacy ***) as a server. I, since Sky is my current provider, have *** Email address is removed for privacy *** as an e-mail address, but choose not to disseminate this as I may wish to change provider at some stage. Following experimentation found I was able to send an e-mail from hotmail, but not receive. Why has this happened and what should I do? At the moment, nobody can send me e-mails, not even Junk gets through!