For how long are the messages stored on the server?

KakaoTalk stores messages on the server for users who cannot check messages immediately.
These messages will be stored on the server for 2-3 days and will then be deleted permanently from the server for your privacy.

Please note that you may not be able to check your messages if you turn off your phone or you are not connected to a network for more than 2-3 days.
Also, if you do not log in to KakaoTalk Desktop for more than 3 days, you may not be able to check messages delievered during that time on your mobile from your desktop.