When did the automatic deletion of 3-day information start?

the first day when the information exceeds 3 days. The function of automatically deleting short messages will automatically delete short messages 3 days ago after being turned on, helping users to automatically clean up old and useless short messages. Short message called short message in Chinese mainland, short message in Hongkong, China and short message in Taiwan Province, China is a kind of mobile phone service, and users can send or receive it directly through their mobile phones or other telecommunication terminals.