Unfortunately some IMAP clients simply don't get on well with some IMAP servers. That is the one real downside of IMAP, it is a very complex protocol (more complex than it needed to be in my opinion). POP3 on the hand could hardly be less complex.

Copying large amounts of data from one folder to another tends to highlight any such issues that the client/server combination has.

Until Dovecot came along getting a reliable server that worked well with a range of clients just didn't seem possible. Thankfully Dovecot made that a lot better, though still not enough to make any of Microsoft's IMAP clients usable when not run against Exchange's IMAP implementation

I'd be surprised if Dreamhost weren't using Dovecot, I've got no experience of how OSX's Mail.app talks to Dovecot, but I do know at least that iOS's Mail.app works well against it.

I'm in the process of fixing the last of the email folders using that temp folder trick. Soon the only problems left will be the inadequacy of the iPhone's Mail program.

Just to make sure I'm not seeing some random issue, can you confirm that your SENT folder on the iPhone shows only your OWN (from) address instead of the address of your recipients? I can't get over that since I've clearly defined that folder as the "sent" folder using the prefs on the iPhone.

Ah yes, I meant to comment on that before. You are seeing some random issue, my "sent" folder behaves exactly as you would hope it would with the recipient's name shown.

Does your sent folder show the correct paper airplane icon in the folder list ?

At one point it didn't (when Mail was using a local folder for sent mail), but currently it does. I had to use Settings to tell Mail which folder on the server "Sent" was the sent mail folder. I can't believe I had to actually do that, but at least the option is there.

To confim it wasn't related to moving messages around from Mac OS, I also sent some new test mail, and it also only shows my name in the list.

The other big thing missing from iPhone's mail client is any type of sorting. It's like the model T of mail clients. You can have everything exactly how you want it, if you want it exactly how it is. "Any color as long as it's black"

Ok, *somehow* the Sent mail listing issue has fixed itself. I didn't do anything since last looking at the folder, except finish trying to fix my 'Older' folder. After a long while, my Mac OS client finished indexing everything itself and I finally checked the iPhone again. Maybe 30 minutes had passed. Sent mail now shows the recipient's name as it should. Phew.

But my mail moving trick has failed to fix the order of the messages in the Older folder... I'll revisit that again later though.

Not sure if you discovered this or not, but in Mail on OS X, you can click a folder, then go to the Mailbox menu, and "Use this folder for..." to set up what server folders map to sent, drafts, etc...