PHP email client Roundcube Modifcation

I have my employees using Gmail ( Google apps ) , I am using Afterlogic's webmail pro as my email client . So the problem is the Gmail Storage problem , if a mail is deleted from the gmail it will be unreadable form the email client . So what you need to do is you need to modify Roundcube and and add a cronjob which runs every 20 seconds which fetches Email from the Gmail using Imap or something and then Add save it to a local database which can be readable from the Roundcube inbox . Each email accounts in the roundcube will be connected to each Gmail username and password it will fetch the eMAILS automatically but the problem is when deleted from gmail it will disappear from mail client . You can create an another form to store and link Gmail credintials relating to each mail addresses ( Or you can get that from roundcube database but it will be encrypted ). You can save them to a Table so that you can use it from fetching . Attachments should also be downloaded to webserver and linked accordingly . The pop3 client in Roundcube mayauotomatically fetch new email , you should cut that link in the core script or delete it and replace it with our fetched copy of message . After fetching the emails from gmail the mail must be deleted from gmail account .