Well, I set up my Gmail adress on BB and it went well I suppose because I received mails, but there are just today's mail (I received my phone this morning) and not the days before... I didn't create any subfolder, did I make any mistake on the settings?
No...BB's are not designed (except in some very rare cases) to replicate your entire mailbox, including all historical emails. Rather, they are designed to begin to deliver to the BB new items starting from the time of activation. So, it is WAD -- Working As Designed.
Occam's Razor nearly always applies when troubleshooting technology issues!
If anyone has been helpful to you, please show your appreciation by clicking the button inside of their post. Please click here and read, along with the threads to which it links, for helpful information to guide you as you proceed. I always recommend that you treat your BlackBerry like any other computing device, including using a regular backup schedule...click here for an article with instructions.