Support Centre

How to troubleshoot error messages that you receive when try to send and receive e-mail in Outlook and in Outlook Express



When you try to send and receive e-mail, you may receive an error message that is similar to one of the following:

  • No connection could be made because the target machine actively refused it.
  • The server could not be found. (Account:account name, POPserver:'mail', Error Number: 0x800ccc0d)
  • Task 'server name - Sending and Receiving' reported error (0x800ccc0f): 'The connection to the server was interrupted. If this problem continues, contact your server administrator or Internet service provider (ISP). The server responded: ? K'
  • Your server has unexpectedly terminated the connection. Possible causes for this include server problems, network problems, or a long period of inactivity. Account. account name, Server: 'server name', Protocol: POP3, Server Response: '+OK', Port: 110, Secure(SSL): N0, Error Number: 0x800ccc0f
  • Task 'SMTP server name - Sending and Receiving' reported error (0x80042109): 'Outlook is unable to connect to your outgoing (SMTP) e-mail server. If you continue to receive this message, contact your server administrator or Internet service provider (ISP).'
  • The operation timed out waiting for a response from the receiving (POP) server 0x8004210a
  • A time-out occurred while communicating with the server 0x800ccc19

You may also receive an error message that includes one or more of the following error codes:

  • 0x800ccc15
  • 0x80042108
  • 0x800ccc0e
  • 0x8004210b
  • 0x800CCC0B
  • 0x800CCC79
  • 0x800ccc67

These error messages may occur if Microsoft Outlook or if Microsoft Outlook Express cannot establish a connection with your e-mail server. These error messages are frequently caused by one of the following:

  • Incorrect account settings
  • Misconfiguration of personal firewall software
  • Antivirus software
  • A bad modem
  • Maximum Transmission Unit (MTU) size
  • Outlook Express has been removed from the computer or the installation is damaged
  • Your user profile in Outlook is damaged
  • An e-mail item on your POP3 server is damaged

To work around this problem, use one of the following methods, depending on your situation.

Method 1: Confirm that your e-mail server settings are correct

For information about the correct settings for your e-mail server, contact your Internet service provider (ISP) or system administrator.

Note: Some ISPs do not permit message routing through another SMTP server while you are connected to their network. To resolve this problem, replace the SMTP server for the other ISP or the other e-mail account with the SMTP server that is associated with the ISP that you use to connect to the Internet.

If you notice that your account settings have been changed to "Localhost" in the Post Office Protocol (POP) server settings and "account name/pop server name" in the Account Name box on the Server tab and you are using Trend Micro PC-cillin antivirus software, disable the POP3 Scan feature (Pop3trap.exe) of the Trend PC-cillin software. To do this, follow these steps:

  1. In the notification area of the taskbar, double-click the PC-cillin icon.
  2. Click to clear the Enable POP3 Scan check box.
  3. Reconfigure your POP3 e-mail account in Outlook with the correct settings.

Additionally, it has also been reported that you may have to turn off the PC-cillin Web-Filter option, the Web Security option, and the Enable POP3 Scan option.

Method 2: Check the configuration of your firewall software

Configure your firewall software to grant access to the Internet for the following files:

  • For Outlook Express: Msimn.exe
  • For Outlook: Outlook.exe

By default, most e-mail clients have to have outbound access on port 25 and inbound access on port 110. For more information about the ports that communicate with your e-mail server, contact your ISP or system administrator.

Firewall software that has been known to cause this problem includes products by the following vendors:

  • McAfee
  • Symantec
  • ZoneLabs
  • Cisco
  • Cygate
  • Sonicwall
  • Freedom Security Zero Knowledge

McAfee Personal Firewall

Check your configuration settings in the McAfee Personal Firewall program and make sure that Microsoft Outlook or Microsoft Outlook Express has full access.

For more information about how to configure McAfee Personal Firewall, visit the following McAfee Web site:

Alternatively, you can remove and reinstall the McAfee Personal Firewall program. The reinstallation process recreates the program signature file that is used by the firewall. Additionally, this process makes sure that both Outlook and Outlook Express are included in the list of programs where Internet access is permitted.

Norton Personal Firewall (Symantec)

If you are running Norton Personal Firewall 2002, Norton Internet Security, or Norton SystemWorks software by Symantec, remove your Norton Person Firewall or Norton Internet Security software. If the problem is resolved, you can reinstall your Norton software and the problem should not happen again.

Method 3: Check your antivirus vendor's Web site for additional suggestions

If your antivirus solution includes an e-mail scanning feature, you may have to do additional configuration to use Outlook or Outlook Express with the antivirus e-mail scanning feature.

Antivirus software that has been known to cause this problem includes products by the following vendors:

  • Symantec (Norton)
  • McAfee
  • Trend Micro (PC-cillin)
  • Panda

For more information, visit the following Web sites:

Symantec:"> Trend Micro:">

We provide third-party contact information to help you find technical support. This contact information may change without notice. We do not guarantee the accuracy of this third-party contact information.

Method 4: Determine if your modem is functioning correctly

Contact the vendor of your modem to determine if there are any known issues or updates for the type of modem you are using.

TimeWarner RoadRunner cable service has confirmed that there is a known problem with the older Toshiba models of their cable modems.

Method 5: Verify the Maximum Transmission Unit (MTU) size that is set on your router

The MTU size set on your router may not let packets larger than a certain size to pass through. These types of errors generally occur if you are connecting to the Internet through a Linksys BEFSR41 router, a Linksys BEFSR81 router, or a Linksys BEFW11S4 router. These routers have Maximum Transmission Unit (MTU) problems that may cause timeout errors when you send e-mail messages.

To resolve this problem, change the MTU setting for your router. For information about how to do this, view the documentation that is included with your router, or visit the following Linksys Web site:

Note: This problem may also occur if there is a misconfigured router or device between the user and their mail provider. These types of devices are known as 'black hole' routers.

Method 6: Remove and then reinstall Outlook Express

If Outlook Express has been removed from your computer or the installation of Outlook Express is damaged, Outlook will not function correctly and may generate one of the error messages that are mentioned in the "Symptoms" section. To resolve this problem, reinstall Outlook Express.

Method 7: Create a new e-mail profile

You may be able to resolve these problems by creating a new e-mail profile.

Method 8: Delete suspicious messages from your mailbox

If there is a damaged message in your mailbox, you can resolve this by doing one of the following:

  • Contact your ISP and ask them to delete any suspicious e-mail.
  • Delete any suspicious e-mail by accessing your mailbox by using your ISP's Web-based e-mail program.


If the error code is accompanied by a timeout error message, you may be able to resolve this problem by increasing the server timeout setting in Outlook or in Outlook Express.

This article originally appeared on the Microsoft website at;en-us;813514

Rate This Article

How useful was this article?

Not useful A little useful Useful Very useful Everything I needed