Today you get no chance for a complete archive service with SCN. Either you chose IBM compliance for Mail and have all internal and external mails archived. This way you create an archive where the users folders get lost and no user can access the archive. Or you chose an external archive service which by design can only archive external inbound and outbound mail via smtp and this is incompliant to German trade laws. This archive can be accessed by the users and does also not contain the folder information.
The journaling service in SCN does not obey the name because it does not deliver the mail body, just some of the attributes of the mail like time/date, sender and subject.
So which option you may chose, you will not get what the compliance rules and the users would expect from a good archiving service.
Just to mention that O365 offers a unlimited in-place (which means inside of outlook) mail archive service which knows all necessary compliance rules and keeps the folders of the users. Want to defend/extend the base? Offer good services!