Hi
Also an Update from my Side.
Tassero (the ESP) also told Rocket Moutain AG to contact me to solve the issue.
I had a first phone call with the responsible @ Rocket Mauntain AG. She also told me that rocketmails.ch has nothing to do with them and that therefore they would never answer the email I sent them. I pointed out that the reply-to header points to rocketmails.ch !
She told me, that they have a partnership with Swiss Post (indeed, that is mentioned on their website) and the recipients used for those emails originates from Swiss Post customers who agreed that Swiss Post uses their data for marketing.
I asked, why they don't mention this fact in the advertisement emails so the Swiss Post customer know where to have their data blocked. She couldn't tell.
I sent them (Rocket Mountain AG and Swiss Post) a request for a proof of opt-in for our affected customers. I have not yet received and reply. I'll call them today :-) )
Mit freundlichen Grüssen
-Benoît Panizzon-