Sync issues with Mail

I use the Mail app to synchronize with my bigpond email account. I get new emails with out any problems. The odd thing is that my folders don't line up. If I create or delete folders they don't always replicate on Mail and I have a number of different "Bin" options in my account on Mail: the one labelled "Bin" has my current deleted items (fine) but also seems to contain dozens of folders (all empty) that I have deleted over the years. I also have "Deleted Items" and "Deleted Messages" neither of which seem to be of any use. I also have "Junk Email" and "Spam" ("Spam" seems to trap junk emails whilst "Junk Email" seems superfluous).

It's very odd and I can't work it out. I've deleted and reinstalled my Mail account a couple of times but the issue persists. HELP!