I am developing a php form that collects personal information from a user. This information is not kept in a database, but will be sent to and email address. Would i need to do this over an https connection? If so please explain why or provide a link where i can obtain knowledge of this. How can hackers access this information if it is not kept online or stored in a data base?
I would say if the information is not sensitive, then you don't have to go for SSL certificate.
For example, if you are collecting the user's firstname, lastname, email address, and a message then you don't have to use SSL.
However, if you are collecting sensitive data like SSN, Bank account number, routing number, Credit Card numbers etc, then it is highly recommended that you use SSL.