Invitation letter - will email work

[harshpareekin]

Hi,
my friend wants to invite me to visit him to US on a B-2 visa. He is a US citizen. I will be staying with him, but i will take care of my own expenses, so i just need an invitation letter from him. I just wanted to know:

a) if he can send an invitation through email, or he needs to send it through post.
b) Will he need to send any other document if he is not sponsoring me other than giving a place to stay.

Thanks,
Harsh

[immihelp]

a. Get original letter by mail.
b. No.