The MYOB Sync Cards feature doesn't remove deleted cards
If you delete cards from your Macintosh Address Book but not from your AccountEdge Cards List, when you Sync Cards, the cards you deleted in Address Book won't be deleted from AccountEdge.
Similarly, if you delete cards from your AccountEdge Cards List but not from your Macintosh Address Book, the cards you deleted in AccountEdge won't be deleted from Address Book when you Sync Cards.