If Outlook Express fails to send or receive email it will usually tell you why on the error tab of the progress window (see figure1). However, sometimes you can't always tell what the problem is from the message, instead you may need to refer to the error number which is shown at the end of the log.


Figure1 - Showing where to find the error number



The most common error numbers and a description of each one are listed below. Click on an error number to see available information to help you fix the problem.

0x800CCC00 - Authentication did not load.
1 Reboot your computer and try again.
2 Check Service Status for mail problems.
3 Setup a new account in Outlook Express, re-entering your mail connection details. It is possible that your account has become corrupt.
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0x800CCC01 - Invalid certificate content. / 0x800CCC02 - Invalid certificate date.
Digital certification of encrypted emails can not be verified. Either your digital certificate is out of date or has been revoked. Get your certificate re-issued by your authority server or try recreating your mail profile.
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0x800CCC03 - User already connected
The mailserver believes that you are already logged into your mailbox:
1 Close all connections on all machines and wait 20 minutes to check again.
2 If you are not logged in on another computer then someone may be using/downloading from your account, or something is wrong with your account.
3 If the problem continues, recreate your mail profile.
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0x800CCC05 - Not connected to server
Outlook Express can't talk to the mailserver.
1 Check you are connected to the Internet (view a webpage). If you are connected, double-check your mailserver address.
2 If you can't view webpages, re-connect and try again.
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0x800CCC0A - Incomplete
1 This is a possible corruption of the pop3uidl file (which records what emails have been downloaded). Close your internet connection and all programs. Search for the file' pop3uid.dbx' and rename it to 'pop3uid.xxx'. Reconnect and try again.
2 If this doesn't work, reboot and try again.
3 It is possible that the mail waiting on the mailserver have been corrupted. This could be caused by a large file attachment, mail missing headers or broken in transit. For POP3 mail you be view the contents of your mailbox by using Webmail. may be able to identify the problem and delete the email causing the problem. Your mail should then function properly.
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0x800CCC0B - Server or maildrop is busy
1 The mailserver may be slowing down because of heavy email traffic. Wait 5 minutes and try again.
2 If the problem continues check the service status page to see if there is a known problem with email service.
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0x800CCC0D - Cannot locate server
Outlook Express can't see the mailserver.
1 Check you are connected to the Internet (view a webpage). If you are connected, double-check your mailserver address.
2 If you can't view webpages, re-connect and try again.
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0x800CCC0E - Cannot connect to server
Outlook Express can't talk to the mailserver.
1 Check you are connected to the Internet (view a webpage). If you are connected, double-check your mailserver address.
2 If you can't view webpages, re-connect and try again.
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0x800CCC0F - Connection closed
Your modem/network was disconnected. If this happens often with dial-up, there may be noise on your phone line, you may need updated modem drivers, or an init string. With a network (broadband etc.) the problem may be with your network hardware or drivers.
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0x800CCC10 - Address not known on server
Outlook Express can't deliver an email because the address appears invalid. Check your spelling of the address and try again. You will need to delete the old message from your outbox to stop the error from repeating whenever you try and send.
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0x800CCC11 - Mailing list not known on server
Outlook Express can't deliver to a mailing list, possibly because one of the email addresses isn't valid (check the spelling). Lots of mailing lists have restricted access, make sure that you are properly subscribed.
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0x800CCC12 / 0x800CCC13 / 0x800CCC14 / 0x800CCC15 - Winsock problems
This error usually means that a glitch has appeared in your network protocols which is making it impossible for Outlook Express to transmit data over the network. A common fix is to re-install TCP/IP. Sometimes just re-booting will get things running again.
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0x800CCC16 - User account not recognized
1 This error means that your username or password are wrong. Check they are right.
2 If they are not wrong, try setting up another identity with the same details. Sometimes accounts become corrupted, creating a new copy of your email account will fix the problem.
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0x800CCC17 - User canceled operation
This error occurs as a result of you pressing cancel during the sending and receiving of email. You may do this if it looked like the process had become jammed or was timing out.
If this problem continues, the file 'pop3uidl.dbx' that logs which emails have been received may have become corrupt. You can do a search for the file and rename it 'pop3uidl.xxx'. Then reboot your system and try again.
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0x800CCC18 - Logon attempt failed.
This simply means that Outlook Express was rejected when it tried to connect to your mailbox.
1 Check your account information (username, password, mailserver addresses)
2 Make sure your account is still active (try and login to the portal and check your mail using the Webmail tool)
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0x800CCC19 - Timeout
This error may be the result of a temporary glitch. try rebooting your system and trying again. If this problem continues, the file' pop3uidl.dbx' that logs which emails have been received may have become corrupt. You can do a search for the file and rename it 'pop3uidl.xxx'. Then reboot your system and try again.
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0x800CCC1A - Unable to connect using SSL
This error indicates a problem connecting using the Secure Socket Layer. Simply turn off SSL in the Outlook Express settings.
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General Errors- Applies to many of the errors on the above lists
The error may have been the result of an application error that may be fixed with a reboot. No further information is available though we recommend that you take a look at Microsoft's Knowledge Base regarding Outlook Express problems.
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POP3 (Post Office Protocol 3) Errors
Problems that occur with POP3 affect the download of your latest emails. These problems occur, either because of a temporary glitch, file corruption, or because your account details are incorrect.

Checking your connection details are correct
Have you changed your account details recently? Make sure that you are not using CAPS LOCK while entering a case sensitive password. There is a quick way to check that you are using the right password and username, by connecting to the internet and using a programme called a telnet client.

Telnet is programme that allows you to access and talk to other computers, in this case you can pretend to be Outlook Express and talk directly to the mailserver. This will allow you to see if it's your email account or Outlook Express that is at fault. (This should work with most versions of Windows).

1 Click the Start button, then RUN.
2 In the RUN prompt, type 'cmd' (on Windows NT/2000/XP) or 'Command' on Windows 95/98/ME.
3 In the new window, type 'telnet mail.metronet.co.uk 110' then click enter. Take care in your typing as you may not see what you type so it's easy to make a mistake. If you do, its best to start again.
4 You should be connected to the mailserver - you should see the response "+OK Hello there" which confirms the mailserver is OK.
5 Type in 'user (yourusername)' and hit the enter key (if your username was jsmith you would type 'user jsmith').
6 You will then get a message +OK Password required -type in 'pass< your password> and click the enter key (If your password was l3tmein you would type 'pass l3tmein')
If it is correct, you will get an '+OK Well done' message. You are now in your mailbox and can be sure that your email account details are correct.
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Testing your access to port 25
You can check to see if your email is being blocked by using a telnet client. If you can connect to the outgoing mailserver on port 25, this will confirm that your problem mostly likely lies with the Outlook Express application, or your settings. To do the test:
1 Click the Start button, then RUN.
2 In the RUN prompt, type 'cmd' (on Windows NT/2000/XP) or 'Command' on Windows 95/98/ME.
3 In the new window, type 'telnet smtp.metronet.co.uk 25' then click enter. Take care in your typing as you may not see what you type so its easy to make a mistake. If you do, it's best to start again.
4 You should be connected to the mailserver - you should see a response that begins with "220." which confirms the port 25 is open. If you don't get the "220" response, either the mailserver is not operating properly (check service status), you're not connected to the Internet or something on your system may be blocking port 25.

If you run your own mailserver and don't limit access to it, our network engineers may have blocked your access to port 25. You will be contacted by support if this happens.
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NNTP (Network News Transfer Protocol) Errors
NNTP allows Outlook Express to function as a USENET (newsgroup) client. Problems with NNTP will mean that you either cannot post to newsgroups or are unable to download the latest posts. In most cases problems will be as a result of incorrect settings or a corrupt news posting. If there is a problem with USENET service, it will be indicated on the Service Status page.
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IMAP (Internet Message Access Protocol) Errors
IMAP allows Outlook Express to store emails on the mailserver, allowing access to all your email, old and new from anywhere you can access email. Problems that occur with IMAP are mostly the same types of problems that occur with the more common POP3 mail system. If you were intentionally using the IMAP service, make sure that your settings are correct.
Because IMAP stores all your emails on the mailserver it is possible that a corrupt email (often with large attachments etc) may be the cause of problems. If you think this has occurred, raise a ticket to support using Contact Us. Our network engineers will then investigate further.
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RAS/DUN (Remote Access Server/ Dial-up Network) Errors
RAS/DUN errors indicate problems with your diaup or network system. Outlook Express is tied to your dial-up settings, so if you open it, while not online, it can either automatically connect, or give you the option to connect. You should check your connection settings within Outlook Express (Click Tools, Options, Connections, Change - to see your settings).
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Winsock (Windows Socket/ Socket2) Errors
Winsock is the Windows component that Outlook Express uses for all its TCP/IP (internet) communication. Winsock errors are usually caused by problems within the application/ operating system, sometimes as a result of bad configuration. They may be temporary in nature, vanishing on a reboot. They may be the result of a corruption within either Outlook Express or Windows.
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More Help
Microsoft's Knowledge Base contains a lot of help for fixing Outlook Express problems. If you continue to experience problems with Outlook Express, it is a good place to look - Outlook Express Support Centre.