> I have now been unsubscribed from the list twice,
> without doing anything my self.

The reason is that the message was bouncing:

   ----- Transcript of session follows -----
... while talking to fpo.mail.dk.:
<<< 421 fpo.mail.dk connection refused from [82.67.192.xx]
<xx @ post4.tele. xx>... Deferred: 421 fpo.mail.dk connection refused from
[82.67.192.xx]
Warning: message still undelivered after 4 hours
Will keep trying until message is 5 days old

Any filters enabled on your side ?