Microsoft Knowledge Base

• The Microsoft Network, version 2.51
• Microsoft Outlook Express version 4.0 for Windows 95

SYMPTOMS

When you attempt to send or receive e-mail on MSN, The Microsoft Network, using Microsoft Outlook Express, you may receive an error message similar to the following:

   An unknown error has occurred. Account: 'MSN Mail', Server:
   'smtp.email.msn.com', Protocol: 'SMTP', Port: 25, Secure(SSL): No,
   Server Response: '501 Invalid Address', Server Error: 501.

CAUSE

This behavior may occur for any of the following reasons:

• The e-mail address specified in your MSN e-mail account settings may not be correct.
• The Microsoft Client for Microsoft Networks may not be installed.
• Your computer's network name may not conform to the naming conventions.

RESOLUTION

To resolve this issue, use the following steps:

1. Start Outlook Express. If the MSN Sign-In screen appears, click Cancel.

2. On the Tools menu, click Accounts.

3. On the Mail tab, click MSN Mail, and then click Properties.

   NOTE: The name of your MSN e-mail account may vary depending on how you configure Outlook Express. MSN Setup creates a default MSN e-mail account named "MSN Mail."

4. On the General tab, under User Information, type your correct e-mail address in the E-mail Address box. Note that the e-mail address must not contain any spaces.

5. Click OK, and then click Close.

6. Open the Outbox folder.

7. Right-click an e-mail message and then click Delete. Repeat this step until all e-mail messages are deleted from the Outbox.

8. Close Outlook Express.

1. Click Start, point to Settings, and then click Control Panel.

2. Double-click Network.

3. On the Configuration tab, verify that Client For Microsoft Networks is listed in the "The following network components are installed" box. If Client for Microsoft Networks does not appear, add the Microsoft Client for Microsoft Networks by using the following steps:

   a. Click Add, click Client, and then click Add.

   b. In the Manufacturers box, click Microsoft.

   c. In the Network Clients box, click Client for Microsoft Networks, and

         then click OK.
   

4. Click the Identification tab.

5. Change the computer name so that it consists only of any combination of letters (A-Z) and numerals (0-9). Do not use non-alphanumeric characters or blank spaces in the computer name.

6. Click OK. When you are prompted to restart the computer, click Yes.