ahmex,
Now that you have gone the 'professional' route with your own domain, you should really think about using MS Exchange. Buying an Exchange server is very pricey, but using hosted Exchange is great. I use The Message Center because they're inexpensive and have great support.
An Exchange configuration is the only way to get E-mail, Calendar, Tasks, Notes synced so that you can see your mailbox anywhere (including mobile devices).
Hopefully your current E-mail provider offers synchronization software for webmail to Outlook that you must download. -- this would be the only way that I know of other than Exchange services to sync your sent items folder using an IMAP configuration. (just be sure to always set it up to leave a copy of mail and sent items on the server)
Hope this at least points you in the right direction with your webmail provider!