I am a small company new to Zoho CRM.

First of all, none of my reminders or alerts seem to be working. Must be doing something very basic wrong but i have done several tests and so far have not received any email or pop up alerts. 

secondly i would like to set up amnautomatic rule that reminds me to follow up on a contact and/or lead 15 days after the most recent modification. im sure this cant be hard but can someone help?

thanks