Restrants not Arriving, Email not Working

Hello

I recently purchased this and have installed and configured on a Joomla 1.5.25 installation.

I have registered a number of participants but none are appearing - in neither the Registrants nor Export Registrant pages (no special characters in use). Paypal payments have gone through and was returned to the ‘payment successful pages’

Secondly, and I imagine this is linked, no confirmation emails are being sent – spam/junk mail folders are empty.

This is an urgent request, anyone with ideas I would love to hear from you.

Thank-you,
Paola