I've had a very polite reply back from
firstname.lastname@example.org explaining that:
We would point out that, within its activity as a provider of electronic communication services, TMN merely provides its clients with access to the Internet, which entails the activity of simply transporting information over the network. TMN is not behind the transmission of illicit information, and neither does it have any part in the selection of the information or its addressees, although it does perform the merely technological storage of the process of transmission exclusively for this purpose and for the time necessary to perform the transmission.
I interpret this "we're happy to take your business, whatever it might be". So, if you want to send spam from Portugal, TMN are for you. I'm sure someone will find this information useful, and I hope that this blog entry makes it easier for them to find it.