Just for future reference, and for anyone else who is stuck, if you look at mail headers of a message from a mailing list you'll almost always see a header like this:
<mailto:corpora-request at uib.no?subject=unsubscribe>
I.e. send a message to <corpora-request at uib.no>, with "unsubscribe" as the subject.
If it is still not working, you may be subscribed with a different address, and your email is being forwarded to your main address. Again, look at the headers, for this one:
Envelope-to: someone at example.com
Then make sure you send the unsubscribe request from that address.