Downloaded attachments in 4.3

Hey guys, I still have the 4.3 on my curve. So, I don't have the option to save the attachment anywhere

But what happens to the attachment after I download it and view it? Does it stay in my internal memory? for how long?

One would think forever until I delete the email, but I do notice that I can go back to the email and view the attachment without downloading it for a few days, but after a few days, I will have to download it again via the blackberry attachment service.....so what happens to this downloaded attachment for a few days? Does it stay in my internal memory? There are some emails I don't want to delete

I've heard different answers that it will stay in your memory until you delete the email, etc.

Does anyone know for sure?

Please, no speculation. only answer if you know the answer with a certainty.

Thank you for your help. I have used the search button