For a new email account that is empty inside, I tested the Windows version and Android version of the client, and found that only after manually entering the server parameters and logging in, will they create a new “DeltaChat” folder in the target mailbox.
This problem will cause the client to always prompt “Connecting…” after the backup is imported unless the “DeltaChat” folder already exists in the mailbox.
If you use “Import Backup” The way it won’t.
The solution to this problem: Import the backup and log in and go to the settings, enter “Account and Password”, re-enter the password or other parameters and confirm.