I'm on the latest release of Thunderbird on Win 10 x86-64. Every time I type 3 characters of an email, I'm forced to wait for 20 seconds while thunderbird does some validation/searching of address books I presume. I attempted to turn off all address book lookups because it makes using email miserable, but this problem persists. How can I troubleshoot? I just deleted Thunderbird and will re-install, but given this was a brand new machine with a new up-to-date install, i'm not confident this will help. Hourglass spins and thunderbird goes into "Not Responding" mode after a few characters are entered.