Do you pay her for the email contact?

I don't believe clients should have the expectation of free services from a therapist. Some do provide those services for free, and some will reply to an occasional crisis situation for free, but to keep the relationship healthy and balanced, mutually beneficial, I'd suggest you offer to pay for the extra services you want to receive. I agree your wants are valid and I personally find email very helpful in therapy.

It does sound like you may need a different therapist though, because this one, like many, isn't offering the level of availability you want. If it's been many years with her, you may also want to evaluate your overall progress with her. Either way, I think compensation for time is critical to a good therapeutic relationship.

Also, 10 years in, if you're not able to manage your distress, I think that's an important area to focus on in terms of skill building, with a method like DBT or other.