Empty Trash is equivalent to compacting for other folders. So after you do an 'Empty Trash', all messages in the Trash are gone for good.

Thanks for the answer

But after that they are not gone for good from my hard disc, they are still there. And I know there is a way to deleted them forever Best regards

If you're talking about overwriting disc sectors, then this isn't related to Thunderbird. If you're that paranoid, you shouldn't get those messages onto your computer in the first place or have the sender to encrypt them. You haven't given any context for why you'd want to do this, so I do stop speculating here.

Paranoid??? Encrypt??

Thunderbird says I have no space to download more messages. I should have... I can empty the trash and compact the folders, that's easy. But I know the deleted messages are still in my hard disc. And I can not download new messages

About 10 months ago I had the same problem and I solved permanently deleting the trash.... in a way I can either remember either find AGAIN in thunderbird solutions (where I found the solution last time)

Best regards

I know the deleted messages are still in my hard disc.

How do you know that?

Thunderbird says I have no space to download more messages.

What is the exact error message? And what exactly are you doing when you get that message?

I know that because I had the same problem a few months ago and I solved deleting the trash for some hard disc folder.. But I can not find the way to do it again...

The message said "there is not enough space for downloading new messages. Try to delete message and compact the folders" Or something like this.

I already deleted and compact and got some space 2 days ago. I got the same message this morning. I deleted all my emails from 4 months ago (and I use my account for working, so it's not the ideal solution) and I can download messages now. But I know I will ahve the same problem in 2-3 days unless I delete the trash from my hard disc.

As I said, maybe I have to delete (or empty) some folder in .thunderbid folder.... but I don't know which one...

Best regards

I solved deleting the trash for some hard disc folder.

Whatever that means. In any case, I think the deleting the Trash thing is a red herring.

The real problem is the error message about the lack of disc space, which you didn't bother to mention in the first place. And you didn't mention what you were doing when you get that error either.

Often enough this kind of error indicates some sort of folder corruption. Therefore, if not done yet, create a full backup of your Thunderbird profile folder. http://kb.mozillazine.org/Thunderbird_:_FAQs_:_Backing_Up_and_Restoring

Then see if this article helps. http://kb.mozillazine.org/Compacting_folders#Compacting_does_not_seem_to_work