Thunderbird

If you have to enter the password for your email account(s) every time you start Mozilla Thunderbird, you can open your prefs.js file

$ find ~ -name prefs.js | grep thunderbird

to find the file. open it, and modify the line that says:

user_pref("signon.rememberSignons", false);

and change false to true. Now start thunderbird again and you should be set.