It looks like we forgot to announce the availability of nPOPuk 3.02 on this forum, and now 3.03 is also available.
3.02 added functionality to underline hyperlinks in received messages (RichEdit).
3.03 adds a little box in the main window to filter the displayed messages. Click in the box where it says "Filter:" and then type; the program will display only messages that match that string, in either the Subject or From column. I found similar functionality in Thunderbird to be very useful in quickly finding a message from a certain sender in a large mailbox.