If you’ve followed our guide on How to properly setup and configure Nokia Messaging on the N900, you might have come across this problem. If try to add a Yahoo email to your Nokia Messaging account at http://email.nokia.com it will tell you: “This email address must be added on the phone.”
You can easily add Google Mail, Windows Live Hotmail, Ovi Mail, and POP/IMAP email accounts at http://email.nokia.com, but not a Yahoo account. The reason is simple, as a Nokia rep explains: “Yahoo is somewhat special for Nokia Messaging in that you aren’t allowed to add Yahoo email addresses on the email.nokia.com website. That’s basically due to legal reasons–per our Yahoo contract we need to disable Yahoo support in a few countries (the list is small and includes US embargoed countries like Cuba) and we can’t really tell what country you are in unless you do it from the phone.”
How to: Adding Yahoo email account to Nokia Messaging



