Hi Guido,
Thanks for your post. There isn't anything built in to fmSpark to receive emails, so you'd need to build this yourself. The MailIt plugin that is included with fmSpark does know how to read incoming mail, so you could use this to grab incoming mail-- ideally from a special address used for your mailings so you weren't trying to parse *all* your emails this way.
You could then crete new records in Journal, setting the Contact ID field in journal to the ID of the contact matching the inbound email's "from" address.
I hope that helps get you started. For more information about the syntax for reading mail with MailIt, download the MailIt demo here:
http://www.dacons.net/fmplugins/mailit/
Best,