I think the madman wants the Germans to take the Jews back, after all, in his mind, it is the German's fault the Jews went to Isreal in the first place. The Germans did not succeed in killing all the Jews and instead foisted the "Zionist" problem on the Islamic world by letting them have some of their prized Muslim desert land. The holocaust did not happen, or else where did all those Jews living on Muslim land come from?
So, again in the mad Iranian's mind, he is probably offering Germany an ultimatum. Take the Jews back or we have every right to attack your interests.
Maybe he just wants a pen pal.
If Germany wants to help, they should release the full text of the letter to expose why Iran can't be allowed to have nukes.
The proper response to the letter is to withdraw the offers and declare publically, that Iran must give up its nuclear program completely, and for nothing, or there will be hell to pay.
But when was the last time anyone saw anything so sensible from a German politician?