If emails from a web based script are not arriving it is likely that they are not being sent, or that they are being blocked at the point of origin. There are a number of things you can check however to ensure that your script complies with DNN4Less sending policys.
DNN4Less filters all outgoing email. These must have a From or To address that is a domain hosted with DNN4Less. Any email not fulfilling these criteria is stopped.
If you are sending email to a customer who has given you their email address, you need to use the domain name of their site (but it does not need to be a valid mailbox, for example firstname.lastname@example.org is a fairly common one to use). If you want the customer to reply to the email you must use a valid account.
DNN4Less' SMTP Filter System limits the outgoing mail from a domain to prevent bulk emailing. The limits are set to allow normal form based email activity to pass unhindered, but stop any persistent attempt to send bulk mail.
Do not use your site for mass/bulk emailing. The SMTP filter system will prevent this, and all attempts are logged. Attempting to bulk email will lead to your site being closed by our abuse department