Offline Processing with Save and Open

To save mails in a local file for offline processing, select the desired messages in any mail list window and press the Save action button (any number of messages may be selected for saving). A standard file-selection dialog appears, like that in Figure 15-11, and the mails are saved to the end of the chosen text file.

Figure 15-11.  Save mail selection dialog

To view saved emails later, select the Open action at the bottom of any list window and pick your save file in the selection dialog. A new mail index list window appears for the save file and it is filled with your saved messages eventually—there may be a slight delay for large save files, because of the work involved. PyMailGUI runs file loads and deletions in threads to avoid blocking the rest of the GUI; these threads
can overlap with operations on other open save-mail files, server transfer threads, and the GUI at large.

While a mail save file is being loaded in a parallel thread, its window title is set to “Loading…” as a status indication; the rest of the GUI remains active during the load (you can fetch and delete server messages, view mails in other files, write new messages, and so on). The window title changes to the loaded file’s name after the load is finished. Once filled, a message index appears in the save file’s window, like the one captured in Figure 15-12 (this window also has three mails selected for processing).

Figure 15-12.  List window for mail save file, multiple selections

In general, there may be one server mail list window and any number of save-mail file list windows open at any time. Save-mail file list windows like that in Figure 15-12 can be opened at any time, even before fetching any mail from the server. They are identical to the server’s inbox list window, but there is no help bar and no Load action button, and all other action buttons are mapped to the save file, not to the server.

For example, View opens the selected message in a normal mail view window identical to that in Figure 15-4, but the mail originates from the local file. Similarly, Delete removes the message from the save file, instead of from the server’s inbox. Deletions from save-mail files are also run in a thread, to avoid blocking the rest of the GUI—the window title changes to “Deleting…” during the delete as a status indicator. Status indicators for loads and deletions in the server inbox window use popups instead, because the wait is longer and there is progress to display (see Figure 15-7).

Technically, saves always append raw message text to the chosen file; the file is opened in 'a' mode, which creates the file if needed, and writes at its end. The Save and Open operations are also smart enough to remember the last directory you selected; the file dialogs begin navigation there the next time you press Save or Open.

You may also save mails from a saved file’s window—use Save and Delete to move mails from file to file. In addition, saving to a file whose window is open for viewing automatically updates that file’s list window in the GUI. This is also true for the automatically written sent-mail save file, described in the next section.