CPanel Email Forward to Codeigniter Controller and Save Message to db

I'm using codeigniter framework 3+. I am able to forward a specific email account to my application. I need to parse the e-mail, and save the message to a database. My software allows users to communicate using email while saving the conversation to a database. If they choose to login to their account, the email chain must be viewed within the application. I need a script that will read the email from an email address, parse out the reference number from the subject field, parse out the message (reply), search for the reference number within the database, and save the new message (reply) within the database. Of course, I required the script to take all steps to ensure security is upheld, such as escaping input, typecasting variables, and any other security precautions. You must have a good understanding of codeigniter 3+ and php. I want to have this script completed within the next couple days. Do not inquire if you are unable to work on this project right away.