Hello, i have an issue with my email, i have made no changes but from today, my thunderbird takes very long time to open. In bottom taskbar it says building summary file for the inbox.. and it takes about 5minute to load inbox list, "26000 letters." Also i can send but cannot receive any letters and i am missing last 3 months inbox mail. How can i try to solve this issue without causing more damage or loss. Thank you.