Good afternoon, I wait to obtain to explain my problem of simple and efficient form. I have in my environment the Exchange 2000 Server configured with Front-End & Back-End. - In the Front-end one I have my Relay of email (smtp, POP) - > Windows 2000 Server Family - In my Back-End I have respective the MailBoxes of each user. - The Back-End is configured in cluster (Active/Passive) - > Windows 2000 Advanced Server - Each user/email account is created way Activates Directory. The services of smtp and POP are to function correctamente. Since yesterday that tenei to try to create an account IMAP in outlook Express, but without success. When entering in the Exchange System Manager I verify that really the coneco saw email arrives at the destination, the problem is in not making the authentication. The authentication saw POP is to function well, without problem some. It would like to know if somebody had a identico problem or where I will be able to go to search more information related with this my problem. I wait to have obtained to explain my problem of a simple form. I will be waits of some feedback of your part, if thus understanding is clearly. Intently, Marcos Pinto