The Prius Online Requiem server will be shut down this coming September 20th, with all characters being transferred to the Aurora server. Players with less than eight players across both servers will not need to take any action when the servers merge. Should a player have more than eight characters on both servers, they will only be able to access the top eight players with the highest levels. Items in player’s inventory, reserve bag and atrium storage will be automatically transferred.
The biggest change this merge will see is that all mail on both servers will be lost, including unopened and saved items. Players must remember to clean out all of the items from their mail prior to September 20th, otherwise it will be lost. To mark this occasion, there will be a special login event, which will reward players logging in from the 10th to the 20th September with a Reserve Bag containing one item.
Source: Game homepage