Best smartphone OS for IMAP e-mail

[Guest NickJ]

I am a smartphone newbie, and I was wondering what OS (Windows Mobile, Palm, Symbian, etc) do you think is best for accessing my IMAP e-mail account. I understand that Windows Mobile Outlook is rather buggy when it comes to IMAP e-mail accounts (not synching changes properly with the server, redownloading messages in large folders etc). Is there another windows mobile e-mail program that will solve this, and does using a different e-mail program mess with the windows mobile UI and feel? Or should I go with Palm or Symbian, and if so which one.

thanks for your help - it's most appreciated.

Nick