How long is Xiaomi's SMS synchronization?

The SMS synchronization of cloud service will be delayed for 7 days to protect the verification code from being stolen. But when asked about customer service, he said there was no such function. For reference only.

At present, the retention period of SMS recycle bin in millet cloud is permanent. As long as the mobile phone keeps in sync, all the short messages in the mobile phone will not be lost, but the manually deleted short messages need to be manually recovered in the short message recycling station.