Count me in on the letter/e-mail vote!
I am a writer, tho....I
MUCH prefer written communication, especially in uncharted waters! I am far more open when I write than when I speak -- especially over the phone.
Writing allows me to say everything I want to say, exactly as I want to say it.....I never fear leaving anything out, or having something come out wrong. There are no awkward silences and no feeling like you are a "deer in the headlights" where all of the sudden, every single thing you wanted to say flies right out of your head!!
I would also prefer to
receive written communication....so I can absorb it all at my own pace....and have it to hold on to, and read, re-read and re-read!

With a letter/e-mail, you can never forget what was said, and there is no pressure to remember every single detail of what is being said (which you will undoubtedly want to do) because you know you have it right in front of you, and always will!
Ultimately, you need to decide how
YOU feel most comfortable!!! You might even ask your intermediary to find out from your birthmom what
she feels most comfortable with.
Whatever your decision, I am so happy for you and wish you and your birthmom a wonderful reunion and continued happiness!
Hugs,
Sally