Question: Is it permissible for a woman to send a photograph of herself via the internet to a man looking to get married, but who lives far away, so he can see her (what she looks like) and decide whether he wishes to marry her or not?
Response: I am not of this opinion.
Firstly: Since it is possible that someone other than the person intended could see the photograph;
Secondly: Because the photograph does not portray the complete truth (reality). So how many photographs has a person seen, and when he sees the one photographed, finds him completely different (in appearance);
Thirdly: It is possible this photograph may remain with this man, even after he excuses himself from proposing to her, however, it remains with him and he may cause mischief with it, and Allaah is the Most Knowledgeable.
Talibatul `ilm 
jazakallahu khaira,wa barakallah feek
Assalaamu`alaykum wa rahmatullaahi wa barakaatuhu..
wa iyyaak ahky…And May Allaah Bless you too.