There is another perspective here, too.

My therapist lets me email, but he doesn't give this option to all of his clients. It seems to be on what he determines each client needs.

Maybe your therapist is being flexible and trying to meet you where you are at and what your needs are. Sometimes it's not always easy to identify needs vs. wants and maybe your therapist needed time to get to know you and what you really need from her perspective?

BTW, what's the point of therapy if you're not there to talk about your issues? Getting them out in the open via email is a great way to start, and I don't think it's unrealistic for a therapist to expect it to come up in conversation in the next appointment. That doesn't mean you're forced to talk about it, but even my T is like, "So you emailed and said X...." If you're really not comfortable about talking about something in person, you can just explain that you wanted to let her know but you're not ready to talk about it quite yet. People I've seen have been really responsive when I've said that.

Sometimes, I personally need some time between disclosing an issue and actually discussing it. I need time to be okay with the fact that someone else knows the "secret".