Why cant i send e-mails?

Why cant I send out emails in Outlook express?

• I have windows xp. And in my outlook express I receive emails. But I get an error messenge when I try to send emails. It always says one of the recipients was rejected by the server. I checked addresses and they are correct. I have sent to these people in the past.It also says server error 550, error no: 0x800ccc7. Can anyone help me?

• Answer:

  There is one thing you can try on your end. Otherwise it's the other end that you are sending it too. In Outlook Express go to Tools, Accounts. Choose your account and then Properties then Servers. Click to select the My server requires authentication check box. Exit and restart Outlook and try again. If it still does it after trying the instructions change it back. The problem is on the other end. Scan for viruses and Spyware.