To the registrars office

While trying to register to the forum, I could not receive an activation mail to my mail address in the t-online.de domain. Is any Moderator or responsible person aware of such a problem? I waited a week, made several attempts until I finally tried with an alternative address (gmx.net), and voilá...here am I. Now you could say all is good that ends good. But I would like to go back to my normal mail address when the problem is solved. Is t-online.de blocking rapid-i.com or the vice versa?
thanks
Chikaya