"Show downloaded pictures automatically" checkbox determines whether the pictures will be shown automatically after downloading or will be just added to the pictures list. Also you can quickly adjust this option by pressing Ctrl+Alt+D or by double-clicking on status bar icon.

"Download selected messages automatically" option determines if the program downloads selected messages automatically. If this option is disabled you can select any messages without putting them into download queue. In this case you can download selected message by double-clicking on them or by selecting "Download selected" context menu item. Also you can quickly adjust this option by pressing Ctrl+Alt+A or by double-clicking on status bar icon.

"Hide uncompleted parts" checkbox determines if the uncompleted parts will be shown in the both "All" and "Partials" tabs or in the "Partials" tab only.

Mark the "Enable thumbnails" option to enable thumbnails creation for the downloaded pictures (if you have a slow PC, uncheck this option to save system resources).

"Show info tips" option determines if the program should show tips for certain actions in the preview window.

"Slide show delay" determines a time delay between slide to slide switching.

"Pictures folder" edit field specifies the location where the downloaded pictures will be stored.