Käännös - Ranska-Klingon - Bonjour, je ne viens pas de mars, je ...

Klingons are abrupt. They do not use words like "Hello", "Good morning", or "Goodbye". "Bonjour" is therefore not translated here.
I translated "je ne viens de Mars" as (literally) "I am not an inhabitant of Mars".
I translated "on peut correspondre" as "we can trade messages".
I translated "bien à vous" as "with honor".
The name "Jean-luc" can either be retained in that original spelling or Klingonized, as I have done.
Capitalization does not exist per se in Klingon. The letters must remain as I give them.