Bulk email

I had what I thought was a best friend during my graduate years in college. After we graduated, we kept in daily contact and even spent time together.Then I heard from her less and less. She’d only email me, on special occasions, to tell me when something great happened to her. When I recently emailed her about something that happened to me, she didn’t respond at all, even though I asked her how she was doing. Anyway, long story short–today she sent a “bulk email” to all students in the same grad. program updating us about all this stuff that’s happened to her. I was glad to hear from her but I’m hurt that she sent this “community email” to all of us even though she never contacted me back personally to keep me updated. Does this mean we are no longer friends? Please share your experiences and reaction. I know I’m taking it rather seriously but I thought she really cared about me. Now it’s like I’m just another old aquaintance. Am I overreacting?
I know it’s not due to a lack of time/being busy on her part. She has time off now…she said so herself in her letter to all of us.