Now you probably ask yourself 'what can you do for me? Well that is very simple, I want to protect you for any kind of possible scam. , no, just for the simple reason I can't verify every step you make, but 'can I do this myself? 'Oh, you want to sell me something', certainly not in the first place, the information in our website could be sufficient for you, if you just use your common sense and normal knowledge of human character, keep both feet on ground and if you are not too credulous, then it's already a start.
Ask specific questions and check if you receive answers on these questions In case you are using an Agency with email forwarding or other mail-services, and your correspondent is not responding on your specific personal questions, this could be a sign of being suspicious.
To be very serious in your intentions and to be very open to her, gives you a response which you can analyze as reliable or not.
Important is to see how your mutual correspondence is developing, about what kind of subjects you both are talking.
Another important thing is to confirm with her if your (original) letters indeed are reaching her.
Try to send copies of your original letters using postal mail or a fax machine at her office (if possible) and ask her if these letters are the same she received through the Dating Agency you are using.