Hi

Here is how you set up your yahoo acount on your N900 without have to use the Nokia Messaging.

Steps:

1) Used "Others" as service provider when setup the account

2) on the incoming server used "imap.mail.yahoo.com"

3) outgoing is smtp.mail.yahoo.com

user_name < --- without the @yahoo.com
your_passwd


The rest u can uncheck.

work great for me!!!