Recently I was chatting with an iPhone user who was frustrated by having multiple folders for his Drafts, Sent and Trash items. If you keep your email filed neatly this can certainly be inconvenient as you may have to look in two (or more!) places to find your mail if you switch devices.
This problem isn’t unique to iPhones; every email program has it’s own naming scheme for folders and they almost never match what mail servers use. The good news is that they all have settings you can change to re-map their defaults to match your mail server.
On an iPhone or iPad you would navigate here:
Settings -> Mail, Contacts and Calendars -> (Your email account) -> Account -> Advanced
…and then tap on each of the folders–you will be given a list of folders on your server to choose from. Once you make a selection your iPhone will put mail in that folder instead of the one that it created with the different name.