When your Windows Live Mail refuses to send messages, you can try the following methods to resolve the Windows live mail won’t send messages issue:
1. Test your spam filtering:
The content of your email might contradict a spam filter from any one of your servers. To eliminate this case, try composing a new message. Add a unique subject along with a few lines of plain text. Then, send the email from the problematic account to the same account. You can be sure that there is no fault from your side in case you get the email. If the issue is not resolved, then have a close look at the bounce email that you receive.
2. Send your pictures as attached files:
If you try to send emails that cause the error 0x8007007, then it means that the Windows Live Mail app is unable to send media attachments from OneDrive. The above situation might happen because of the most recent updates on OneDrive. Therefore, you have to try sending your pictures as attachments.
3. Confirm that you use the same settings as that of your incoming mail server:
4. Try deleting the corrupted emails in Outbox:
In some cases, the Windows Live Mail app might retain the unsent emails in the Outbox folder. Also, you will be sure that your emails are not reaching the intended recipients. This scenario indicates that one or more of your emails could be corrupted. The above situation generally happens with the oldest of your emails. Therefore, try deleting such emails one after another. The above methods should help you fix the Windows Live Mail won’t send messages issue.