As of June, Miles&More will not respond to letters they receive in kind. They will only dump their boilerplates into a special "Inbox" which you have to seek out in your Miles&More account.

"From this June onwards we will be sending our responses to any personal enquiries you make by letter directly to your personal inbox only. (...) ‘Snail mail’ will therefore be consigned to the past.

A short notification e-mail will always tell you when such a message has arrived in your inbox. To ensure you receive messages, you only need to check that the correct e-mail address has been entered under ‘My Profile’ > ‘Address and contact details’.

Why not simply check your inbox regularly — it will be well worthwhile."

Cui bono...