, i need advice please.4 days ago a dear close friend

hello, i need advice please.4 days ago a dear close friend for the past 15 years passed away with heart disease.we were in a relationship for years but then remained very close friends. he died at his mothers home where he lived alone as few months ago she had to go to a home with dementia.the home is in somerset. he has a brother who lives in london who is a solicitor. i was written a letter off my friend and his last will and testament in event of his death, which he told me to get having left it in his fathers old red tin. i live a distance away in south wales. as his death was sudden i was told by his neighbour who found him. she now has the key. his brother is unable to get down at the moment. we spoke on the phone and i told him that i have been left a letter to read in the tin, which has my name on it. he told me that as he will be in charge of the house now that he would need to open it first without me being there as he needs to see anything legal.i asked if the neighbour could send it to me or he could send it to me unopened first. i need to know if he can open a letter addressed to me without me being there?? im a bit worried as he is a solicitor and i was told by my close friend that he wanted to leave his small savings to me and my daughter.id be glad of some advice thank you beverley