We are currently unable to send emails, everything was fine yesterday evening but when I've tried to send an email this afternoon the message I am recieving is

This account is currently blocked from sending messages. If you don't think you've violated the Windows Live Terms of Use, please contact customer support.

Our email address is {removed email address}

If you could resolve the problem asap that would be great.

Hi knaresborough community centre, 

I have reviewed your account and have found out that our automated spam filters blocked it. I have unblocked your account.  

To help prevent your account from being blocked again, use these tips:  

- Check your contacts and recipients lists to make sure that only people who want to receive the messages will receive your messages.

- Reduce the number of messages that you send to large groups of people so that they are less likely to think your messages are unwanted mail.

-  Limit the number of chain letters, e-mail jokes and other messages that you send to help people recognize your mail as wanted and to make it more likely that your message will be allowed past your recipients' junk mail filters.

- Check all the contacts in your address book to make sure that the accounts are still active.