Given the sending problems with the default Yahoo! push account, plus the fact that you cannot get the iPhone to recognize the Yahoo-specified "reply to" address, I would love to be able to configure a Yahoo! push account manually with my own mail provider's SMTP settings for sending mail. The only problem, of course, is figuring out Yahoo!'s IMAP server settings. I tried using the widely-circulated one: "imap.apple.mail.com" and when trying to authenticate the account, iPhone reported that it could not find the server. I then tried "imap.apple.mail.yahoo.com" with more luck. This time, I received a message that my username or password were incorrect. I then tried a bunch of different configurations of my Yahoo! username but couldn't find one that works. Anyone have any ideas on the proper settings, yet?