XCLN: Error Message: Messages Can Be Received But Not Sent

ID: Q225538

The information in this article applies to:

Microsoft Pocket Outlook, version 2.0
Microsoft Exchange Server, version 5.5
Microsoft Exchange Windows 95/98 client, versions 4.0, 5.0
Microsoft Exchange Windows NT client, versions 4.0, 5.0
Microsoft Outlook Windows 95/98 client, versions 8.0, 8.01, 8.02, 8.03, 8.04, 8.5, 9.0
Microsoft Outlook Windows NT client, versions 8.0, 8.01, 8.02, 8.03, 8.04, 8.5, 9.0

SYMPTOMS

If you send mail from Pocket Outlook or any POP3 client connecting to an Exchange Server computer, you may receive the following error message:

Messages can be received but not sent. SMTP server unavailable.

The text of the message may be different depending on the client used. For example, using Microsoft Outlook Express version 5.0 the error message appears as follows:

An unknown error has occurred. Account: 'SMTP', Server: 'Servername', Protocol: SMTP, Server Response: '421 bogus.domain.com connection limit reached', Port: 25, Secure(SSL): No, Server Error: 421, Error Number: 0x800CCC67

Using Outlook 2000, the error message appears as follows:

The TCP/IP connection was unexpectedly terminated by your mail server. If this problem persists, contact your LAN Administrator or Internet Provider.

CAUSE

The maximum number of inbound connections the Internet Mail Service (SMTP server) can accept at one time has been reached. The most precise of the above error messages is from the Outlook Express client, but be aware that if there are many SMTP clients attempting to send mail simultaneously, one of the other errors above may be displayed.

RESOLUTION

The SMTP server runs under the Internet Mail Service in Exchange Server. To resolve this issue, increase the maximum number of inbound connections for the Internet Mail Service. This value is set to 30 by default.

To change this value, perform the following steps:

Start the Exchange Server Administrator program.

In the left pane, under the organization name and the appropriate site, click Connections, and in the right pane, double-click Internet Mail Service to open its properties.

Click the Connections tab, and then click Advanced.

Set the Max No. of Inbound Connections to a higher number, such as 100. This number may vary; increase it until the problem is alleviated.

WORKAROUND

If you are unable to change the settings on the SMTP server, send your e-mail at another time.

MORE INFORMATION

To reproduce the behavior, set the Max no. of Inbound Connections to zero. You receive the error message on the Windows CE device every time you try to send mail.

To verify that you are experiencing this issue, open Windows NT Performance Monitor and compare the Max No. of Inbound Connections value on the Internet Mail Service with the following counter:

Object: MSExchangeIMC
Counter: Connections Inbound

If these values are equal or even close, increase the Max No. of Inbound Connections value on the Internet Mail Service.

Additional query words: ims

Keywords : exc55
Version : WINDOWS:2.0,4.0,5.0,8.0,8.01,8.02,8.03,8.04,8.5,9.0; winnt:5.5
Platform : WINDOWS winnt
Issue type : kbprb