i'm having a annoying problem :
1 - i've installed some month ago Thunderbird on my USB U3 Smart key 512Mb
2 - a few days ago I realized my Key was soon going to be full
3 - Ok, I decide to erase some heavy emails
4 - but, bad news the size of the Inbox file is not getting smaller as I erase my emails !
what I've I donne wrong and what can I do ?
thank you in advance