You must be logged in to create or reply to a post or private message. If you are logged in, but still having trouble, you may need to verify your email. First check for an email from Boost Mobile Community. If it is not in your inbox check your Spam folder. Once you locate it, click the link in the email to verify your email address. You should now have access to replay or create new discussions and send/receive private messages.
If you no longer have the verification email, you can send it to yourself again. Go to your profile and click on My Settings: Email , then click the button to resend the verification email.