In a message posted to Aion's Facebook page and on the official website, NCSoft announced they are bringing the servers down this morning for "weekly server maintenance."
Beginning at 3 a.m. PDT and estimated to last approximately 4 hours, the maintenance includes a small patch with some language corrections and a spam filter upgrade.
While there has not been a defined 'maintenance' day of the week, NCSoft has brought the servers down for short periods during the last three weeks. The player base has been clamoring for a consistent maintenance schedule.
Game version 1.5.0.11 restricts all chat channels to characters of level 10 and higher. While all characters can receive whispers and mail, only those who have reached level 10 can initiate those methods of communication.