I don't know whether this is relevant, but I can access my Yahoo! account on my BlackBerry Pearl. I just enter in my user name and password, and the Pearl accesses on my account. It marks a message as read in my Yahoo! account when I read it, and I can delete the message from both the Pearl and the Yahoo! account.
If Hotmail and Yahoo! work similarly--and you can access a Yahoo! account on an iPhone--you may be able to get your mail.