Microsoft KB Archive/199164

= XCLN: Error 505 Authentication Required in Outlook Express =

Article ID: 199164

Article Last Modified on 2/27/2007

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APPLIES TO


 * Microsoft Exchange Server 5.5 Standard Edition
 * Microsoft Exchange 2000 Server Standard Edition

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This article was previously published under Q199164



SYMPTOMS
When you use Microsoft Outlook Express to send messages by means of Exchange Server 5.5 or Exchange 2000 Server, you may receive the following error message:

An unknown error was returned from the SMTP server. Subject, Account ' ', Server:  , Protocol: SMTP, Server Response: '505 Authentication required', Port: 25, Secure(SSL): No, Server Error: 505, Error Number: 0x800CCC61.

Post Office Protocol version 3 (POP3) and Internet Message Access Protocol (IMAP) clients in Outlook Express may receive the same error message.



CAUSE
This issue can occur if the Internet Mail Service in Exchange Server 5.5 or the SMTP connector in Exchange 2000 is configured to require authentication, and Outlook Express has not been configured to send authentication credentials.



RESOLUTION
To resolve this issue, configure Outlook Express to send authentication credentials:
 * 1) On the Tools menu, click Accounts.
 * 2) Click the current user account.
 * 3) Click Properties.
 * 4) Click the Servers tab.
 * 5) Under Outgoing Mail Server, click to select the My server requires authentication check box.
 * 6) Click Settings.
 * 7) In the Logon Information dialog box, select one of the three following options:
 * 8) * Use same setting as my Incoming Mail server. The authentication credentials in the Incoming Mail Server option.
 * 9) * Log on using. Type the user account and password of the current user.
 * 10) * Log on using Secure Password Authentication. An authentication credential is displayed every time a message is sent.
 * 11) Click OK until the Internet dialog box appears, and then click Close.
 * 12) Compose a new message and send it.



MORE INFORMATION
Exchange Server 5.5 provides the option to enable connections to the Internet Mail Service using credentials. You can set this option in the Internet Mail Service properties, on the Connections tab, by clicking Accept Connections. If you select Only from hosts using Authentication and Clients can only submit if homed on this server, any POP3 or IMAP client must be verified before connections are enabled.

Exchange Server 2000 also provides this option. To enable connections to the Simple Mail Transfer Protocol (SMTP) virtual server by using credentials, you must enable the type of authentication required on the Access Tab under Authentication on the SMTP virtual server properties. Anonymous access does not have to be disabled to enable authentication. However, Microsoft suggests that if authentication is required, anonymous access is not enabled.

NOTES:
 * By default, Exchange 5.5 is configured to accept connections from any host (Anonymous).
 * By default, Exchange 2000 is configured to accept anonymous access, basic authentication, and integrated Windows authentication.
 * Enabling anonymous access on the Exchange 2000 SMTP Virtual Server does not allow the client to send messages to Internet recipients. This is frequently referred to as relaying mail. For clients to relay mail by using a default configuration for the Exchange 2000 computer, authentication must be configured on the client.

Additional query words: exch2kp2w IMS

Keywords: kberrmsg kbprb KB199164

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