What would be required to email users several weeks before the end of their first year? I'd thought of a flag from admin that could be set (turned off for check payments), so an email would be sent to their webmail as well as alternate address. This would be for credit card orders, users who were paying for their webmail service. It would be a reminder that payment was due etc.
It would work on the creation timestamp. I'd need to be able to set it to send at different times. I'd enter the email to be sent from a box in admin. Only those users with their checkbox selected would receive the email at yearly intervals.