benoît237 wrote:
Thank you very much. So you can not create a folder on iCloud without having it on the Mac. :(
Correct.
But can I synchronise a user on two machines? The "Office" Mac and the MBP for the trips. When I say "user" I mean documents and the Library folder, like keychain or mail (I still have some POP/SMTP accounts).
Yes. You can turn on Desktop and documents to sync those folders across the Macs so all files are kept up to date.
POP email accounts are by their nature not synced. What you download on one computer is removed from the server, so other devices accessing said accounts would not see the emails anymore. IMAP email accounts keep email on the server and as such can automatically sync between different devices, since all changes and updates are done on the server.
Or, si Time Machine my only solution?
If you need to keep files off the computers then either Time Machine or some other backup software, (there are many 3rd party alternatives) can do that.
By definition archived content is content which you don't need to access constantly much less from multiple locations or devices. So yes, backing up to an external drive is a good and recommended way of archiving files.