Dear Anna,
sorry, I forgot to mention, I am on a Small Business Plan (Exchange Online Plan 1).
And yes, my domain is "kwiloo.net" and it is verified. I followed the initial steps as described in the online help of OL365, and my admin page states that my domain is verified (though not "active").
Can you please advise into which of my newly created sub-domains ("autodiscover.kwiloo.net" or "ms229xxxxx.kwiloo.net") I should enter the MX value and the CNAME value, respectively. The link you provided does not provide the answers as 1&1 either changed their settings since these instructions were drafted or it maybe just my plan with them that does not allow me to follow these steps. That's why I followed the instructions in a forum on the internet and cretaed these two sub-domains.
Thanks!