Before importing addresses from outlook Express, you need to save your addresses of Outlook Express in CSV (Comma separated value). Then log on to your Rediffmail account and
Click onto the option of Address book
You will get the list of addresses and on the top the options given as Add New, Import, Send Mail, Add to Group, Edit and Delete.
Click onto the option of Import.
You will get the drop down as Contacts From and Buddies From.
Click onto Contact From and select the option of Outlook Express from the drop down list that is been shown.
It would give you a box which will have the message as Select the Address Book File:
Click onto the option Browse and select the file of addresses that you had saved.
Click onto Import Address Book at the bottom and it will starting importing the addresses accordingly.
Once you have done, you will find the addresses in your Rediffmail account address book.