You can remap IMAP source folder to destination folder. It’s very likely that sent folder needs to be remapped between different hosts. I suggest you to use the dry-run option and examine the log to see if the folders are correctly mapped.

More in detail, I created an user just to run imapsync as a good practice in Linux. Then downloaded imapsync in a subfolder of the user home directory, created two very simple scripts, one with the imapsync command with all the parameters I needed and one for the token. Lastly, using crontab -e, I added two entry one for each script.

You don’t need to put imapsync into etc, it is not a binary and, as far as I know, there is no package that you can install with a package manager, it’s just a script that you download and execute. Anyway, where you put that, its up to you.