Microsoft KB Archive/298589

= OLEXP: You Are Repeatedly Prompted for Credentials When You Log On to Your Mail Server =

Article ID: 298589

Article Last Modified on 1/31/2007

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APPLIES TO


 * Microsoft Outlook Express 5.5
 * Microsoft Outlook Express 5.0
 * Microsoft Outlook Express 5.5
 * Microsoft Exchange 2000 Server Standard Edition
 * Microsoft Exchange 2000 Enterprise Server
 * Microsoft Exchange Server 5.0 Standard Edition
 * Microsoft Exchange Server 5.5 Standard Edition
 * Microsoft Outlook 2000 Standard Edition

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This article was previously published under Q298589



For information about the differences between Microsoft Outlook and Microsoft Outlook Express e-mail clients, click the following article number to view the article in the Microsoft Knowledge Base:

257824 OL2000: Differences Between Outlook and Outlook Express



SYMPTOMS
When you connect to Exchange Server 5.0, 5.5, or Exchange 2000 to send or receive mail in Outlook or Outlook Express, you repeatedly receive a prompt for credentials.

With Outlook Express, the following information may be displayed on the Error tab in the Details box:

The message could not be sent because the server rejected the sender's e-mail address. The sender's e-mail address was ''. Subject '', Account: '', Server: '', Protocol: SMTP, Server Response: '454 5.7.3 Client was not authenticated.', Port: 25, Secure(SSL): No, Server Error: 454, Error Number: 0x800CCC78

The message could not be sent because the server rejected the sender's e-mail address. The sender's e-mail address was ''. Subject '', Account: '', Server: '', Protocol: SMTP, Server Response: '505 Authentication required', Port: 25, Secure(SSL): No, Server Error: 505, Error Number: 0x800CCC78

There was a problem logging onto your mail server. Your User Name was rejected. Account: '', Server: '', Protocol: POP3, Server Response: '-ERR Clear text passwords have been disabled for this protocol', Port: 110, Secure(SSL): No, Server Error: 0x800CCC90, Error Number: 0x800CCC91



CAUSE
The Exchange Server computer has been set to only allow Integrated Windows Authentication.



RESOLUTION
If you cannot receive messages properly in Outlook Express or Outlook 2000 Internet Mail Only:
 * 1) Start Outlook 2000 or Outlook Express, and click Accounts on the Tools menu.
 * 2) In the Internet Accounts dialog box, click the Mail tab.
 * 3) Click your mail account, and then click Properties.
 * 4) Click the Servers tab, and then click to select the Log on using Secure Password Authentication check box under Incoming Mail Server.

If you cannot send messages properly in Outlook Express or Outlook 2000 Internet Mail Only:
 * 1) Start Outlook 2000 or Outlook Express, and then click Accounts on the Tools menu.
 * 2) In the Internet Accounts dialog box, click the Mail tab.
 * 3) Click your mail account, and then click Properties.
 * 4) Click the Servers tab, and then click to select the My server requires Authentication check box under Outgoing Mail Server.



STATUS
Microsoft has confirmed that this is a problem in the Microsoft products that are listed at the beginning of this article.

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MORE INFORMATION
For additional information about security settings in Exchange Server 5.5, click the article number below to view the article in the Microsoft Knowledge Base:

200788 XFOR: POP3 or IMAP4 Client Cannot Send SMTP Mail

Additional query words: pra oe

Keywords: kbbug kbpending KB298589

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