First off, this should be in the "Problems&Bugs" section.
If your having e-mail sending problems, your SMTP settings are incorrect.
In your mail.config or web.config (depending on version), your SMTP settings should look like this...
Code:
<smtp from="myforum@mydomain.com" deliveryMethod="Network">
<network host="smtp.myprovider.com" password="mypassword" userName="myusername" />
</smtp>
If your using a third-party supplied SMTP Host, they may have SMTP relay turned off. In this case, you need to contact your provider for SMTP settings to get this working.
HTH
.....the man in black fled across the desert..........and the gunslinger followed.....