Why can I not send my e-mail?

Please help. I sent a bunch of email today and suddenly outlook express can't send anymore. Why?

• I used mail merge to merge the email to send to about hundred of people. In order to save time, I used mail merge of microsoft words to merge the email with the data record. After I merged them, I sent those mail by clicking ok 100 times. Apparently words sent the email using outlook express. I use outlook express to receive and send my msn email account. I realized that not all of those email were sent. They are left in the outbox about half of them. The outlook can't send any email at all, but it can receive email. I do not know what is the problem. Is it the firewall, the internet connection or the outlook express itself. It keeps asking me "do you want to send these emails now?" Then, I click ok, but came up an error message said precondition failed. How can I fix this outlook express so it can work normally? Thank You.

• Answer:

  Probably over quota with your IP service or it's not set up correctly. Yahoo especially limits the number of e-mails you can send.If you send too many they want you to set up a web page and provide a link to your e-mail others would click on the link and see the e-mail on your 360 page.