This change will begin 27 September for new users and become effective for all users worldwide in 2005 after extensive communications to our existing users.
Microsoft says it decided to start charging for the service as it was being abused by senders of spam.
In the past, people could download e-mail from Hotmail into Microsoft Outlook and Outlook Express for free.
But now only people who had paid an annual subscription fee will be able to access their messages without opening a browser window.
Users who want to use Outlook to pick up their Hotmail messages will have to pay $19.95 (£11) for an annual subscription to Hotmail Plus or the $99.95 (£55) a year for MSN Premium.
But subscribers who are already using the technology to download their messages will be able to carry on using the service for free until April.
