What does “Compact” do to an address list?
PC-Xpedite for Windows stores each address list in a database file. A database file can become fragmented as you make changes to it. Over time this can result in a significant amount of wasted disk space. Compacting a database reorganizes it to reclaim this wasted space. If PC-Xpedite for Windows detects that your database is very fragmented, it will ask you if you want to compact your database when you save it.