Email is more helpful than phone for me in certain circumstances because I can go back to what I said/felt at the time and what my T said and try to integrate the two halves. It's easier to hold onto both sides with email compared to something more ephemeral like a phone call where my emotions are so strong and I'm likely to mostly forget the supportive things my T says. But if I'm really upset or need to work through something or need to feel the connection more, then phone is still the way to go for me.