Houston Consulate is most definitely open.
They won't respond to any questions related to a visa.
If you are Russian citizen and in need of a Russian passport, and you can write to them in Russian you may get a response. However - No appointment is necessary if you need a Russian passport. However you will need to go the security desk, they will phone the consulate and send someone down to take you up. This happened when I was there.
If you have any other business there, you will need an appointment. Also, you will need to show proof of the appointment at the security desk before you will be allowed to take the elevator up. They are on floor 13. The elevator that you have to use only goes to floor 13 (elevator C).
I was able to give them a pre-paid envelope to mail me back my passport with Russian visa. So I didn't have to go back again. It worked out fine.