To transfer an address book from Outlook Express to a different email program, you first must export the address book in a universally readable format, such as CSV. To do so, go to the Outlook Express menu, click on File, go to Export, and then click Address Book. Select Text File, click Export, save the file to a suitable location, and click Next. Choose the fields you want in the exported address book, and then click Finish.
The procedure varies slightly for later versions of Outlook. For Outlook 2003 or 2007, go to File, and click Import and Export. Next, click Export To a File, and click Next. From the list that appears, click on Comma Separated Values. From the list of folders, click Contacts, and click Next. Select a location for the file, and then click Finish.
For Outlook 2010 or 2013, click File, go to Options, click the Advanced option located on the left navigation pane, and then click Export. From there, the Export Wizard is similar to that of Outlook 2003 or 2007. The procedure for exporting is also the same.
After exporting the address book from Outlook, locate the Import option in the other email program, and import the address book you created.