There are two sub-tab pages in a tab page of a mailbox. The "New Messages" page list those messages that are gathered in the last download. The "Old Messages" page contains those messages that are already downloaded, including those listed in in the "New Messages" page, which are decorated in red. Both of them has an operation band on top. The operations on the "New Message" page are mainly for downloading new messages whereas in addition to these, the ones on the "Old Message" page are also for operations on the set of messages that are already downloaded.
A downloaded message can be in three state: 1) it's remote copy has not been deleted; 2) it's remote copy had already been deleted, only local copy is present; and 3) the local copy was deleted but the remote copy is present.
The "Downloaded Messages" tab page inside "Old Messages" list the messages for which both remote copy and local copy are present and the "Other Local Messages" page list all those messages whose remote copy had already been deleted (see Fig: 9).
The processing of mail messages starts when a user presses the "Start Processing" button. But before processing, a user needs to specify 1) what is going to be performed on the messages (the action), 2) what is the target and 3) which messages are going to be affected by the action. The processing is meaningful only after these aspects are specified.
The current version of the program supports only "delete" action. The available targets are listed inside the dropdown boxes to right of the "Default Target". It includes "Remode Copy", "Local Copy" and "All Copies". One of them should be selected as the target. For example, when the target is "Remote Copy", the action only affects the remote copy of a selected message. The meaning of the two targets is also obvious. Here the default target can be overridden as long as the user selects a non-empty and different target inside the dropdown window of a particular message.
The left most checkbox for each message in the list is used to select it for operation. For those users who seek convenience, the three buttons on the top band can come in handy, which are "Select All", "Deselect All" and "Revert Selection". They only affect the selection status of the messages in the current message page. The selection status will not be changed when the user changes a message page so that item selection can be set across message pages before processing. As an example of their usage, let's suppose that a user wants to delete most of the messages on a page, he/she could first select all messages and then uncheck those small number of them which are to be kept.
A side note: 1) if a user delete only a local copy of a message, it will reappear after the next download; 2) after the user start the program and before the first download, all messages will only be shown inside the "Other Local Messages" tab page since information about their online presence has not been gathered. The second characteristic is a limitation of the current version of the program, which will be improved when newer version of the same system is released.