Hello, we've just configured a server to host moodle on a machine running in Windows Server 2003 with Moodle 2.1 on our campus. The configuration goes well but when we create new accounts and hit Create My New Account button, Moodle prompts us "Tried to send you an email but failed!".

I already enabled "Self Enrolment" module under Site Administration->Plugins->Enrolments->Manage Enrol Plugins. I've also enabled "Email-based self-registration" in Site Administration->Plugins->Authentication->Manage Authentication and already set "Self Registration" field to have a value "Email-based self-registration" under "Common Settings" but still the same message appears "Tried to send you an email but failed".

Did I miss an important configuration? Please help. Thanks in advance.