Lady Snowdon - your ex-friend has treated you abominably. I'm appalled by her behavior. I'm also a little
that she doesn't even seem to care about getting her dress back. I think after two years, you can safely consider the dress abandoned property. As it now belongs to you, I think you're free to do what you like with it. Like other PP's, for your peace of mind I would suggest setting up a free email address with yahoo or gmail or whatever so that you can send her an email if it's indeed true that she's blocked your email address. Then, give her one last firm deadline (10 days should be more than enough) for her to either come and get the dress or make arrangements for someone else to get it - or arrange delivery and pay for it. You have been more than kind and generous to her.
I also think she owes you storage fees, although I understand if you don't want the drama of pursuing that with her - it's just that she really does owe you for that, in case she ever wants to make an issue of anything...KWIM?