I really like this script, it has a nice interface, nice feature.
I am aware of this being maybe a little off-topic, nevertheless it is almost already a ticket system as it is.
My suggestion goes to adding ticket handling to the script, that is a web form that clients can enter a support requests in. Also a mail-interface, so that incomming e-mails to support@domain.tld is created as a task and a reply mail is sent with the ID in subject. The tickets could easily just be tasks in a project called "Raw" or "Unsorted", then the staff could set who is responsible, which customer and project this is for. Also one could make a project for each customer called "raw" or "unsorted", so that incomming e-mail would be sorted to this folder if senders e-mail is in that project.
Addition of this feature would make you software ideal for IT-companies like ours, that have lots of support- and project orientated work. As of now we are using a ticket system, a worklog system and a project system to keep things running, but your system could in time replace all 3.
