Messages are your e-mails, newsgroup articles, drafts (unfinished messages) and templates. You store them in folders. Messages menu contains all commands necessary for managing them and message popup menu (recalled with right mouse button while pointing a message) allows for fast access to the most frequently used commands. Messages are easy to sort - click on a column above message list and it will be sorted by that column. Second click reverses sorting order. You can enable and disable threaded view by clicking first (leftmost) column. To move messages into another folder, select them and drag into destination folder. Hold down CTRL key while dragging to copy them instead of moving. To quickly create filter that moves similar messages into chosen folder, drag them while holding an ALT key. This will display filter editor window in which you can either accept programs suggestions or customize them to fit your needs.
Messages may be flagged, colorized, marked as read and unread, thread messages can be marked as watched or ignored. Ignored threads are always on bottom and watched threads are always on top of the list - regardless of sort order. Messages have their "status" - every time you forward them, reply to them, read, mark as unread, etc. program denotes this and presents messages with different icons.
Newsgroup articles are special kind of messages because they can't be moved - only purge or filter out. Attempt to move message into another folder will cause it to be copied and you cannot move messages from any source into newsgroup folder. Messages that don't have body stored locally are denoted with small yellow dot in the icon's corner.