Thunderbird

I am one of the happy users of the Thunderbird ! So for I am enjoying it. Recent days I found few good enhancements can be added:

1. If I click on Search when I am in "Sent" folder, it is good if the search criteria is changed automatically to "To or CC". Because I search only the email which sent to particular address. I agree subject can be other option
2. If there is a login screen then it will be good so that nobody can't read the email. For example I give my computer to troubleshoot to sysadmin , it will be useful during that period. I agree user can directly open the files and read the email, I suggest to store in non readable format
3. Tagging is one of the good features. All emails will goto one default folder the emails can be grouped based on the tags.

I am sure lot of other good enhancements can be added but I got few