Outlook Error 0x80040900 – How to Fix It

Did you encounter error 0x80040900 when clicking Send/Receive in your Outlook email client? This error usually occurs if you have specified an incorrect email server name or port in your Outlook account settings. It can also occur if the email server is unreachable due to internet connection problems.

In both cases, you will receive the following error message during the process of sending or receiving an email:

The "info@vasadomena.si - receiving" task has an error message (0x80040900): "The server name you entered cannot be found on the network (it may be temporarily unreachable). Please check your connection to the Internet and the correctness of the server name".

Or in English:

Task 'info@vasadomena.si - Receiving' reported error (0x80040900) : 'The server name you entered cannot be found on the network (it might be down temporarily). Verify that you are online and that the server name is correct.'.

How to fix Outlook error 0x80040900?

First of all, make sure that the device on which you want to access your Outlook email is definitely connected to the World Wide Web. Open your browser and make sure that the Internet connection is established by visiting any web page.

1. Check your email server settings

To set up your email server correctly, you will need to know the following information:

• Incoming mail server type: POP3 or IMAP?
• Name/address of the incoming mail server.
• Name/address of the outgoing mail server.
• Port number of the incoming mail server.
• Port number of outgoing mail server
• Does the outgoing mail server require authentication?
• Does the mail server use SSL?

If you host your email on our server, you will find all the information you need HERE.

Now follow the procedure below:

1. Open your Outlook email client.

2. Go to File -> Account Settings.

3. In the Email tab, double-click your email account to view or change settings.

4. Make sure that you have set the correct incoming and outgoing server name.

NOTE: Do not enter the information shown in the picture above. Enter your domain information!

5. In the bottom right corner, click on the More Settings … button.

6. If the outgoing server requires authentication, in the newly opened window – in the Outgoing Server tab – add a tick to the above setting.

7. Then, within the same window, move to the Advanced tab and make sure that you have the appropriate ports (993 and 465) configured and the SSL connection selected.

8. Save the settings change by clicking OK and check that sending/receiving email is now working.

2. Check your antivirus and firewall settings

If you are using an antivirus program with the ability to scan emails, try temporarily disabling it and check Outlook again. In addition, check your firewall settings and make sure that the email server port you are using is not blocked by the firewall.

Specifically, in the firewall settings:

1. Allow the following file to access the Internet:
   • Outlook.exe
2. Allow the following ports to access the Internet:
   • 110 (for POP3 incoming mail server without encrypted connection)
   • 995 (for POP3 incoming mail server with encrypted connection (SSL enabled))
   • 143 (for IMAP incoming mail server without encrypted connection)
   • 993 (for IMAP incoming mail server with encrypted connection (SSL enabled))
   • 25, 26 or 587 (if the SMTP outgoing mail server does not use SSL)
   • 465 (if the SMTP outgoing mail server uses SSL)

3. Restart the router

You can also try to resolve Outlook error 0x80040900 by restarting the router. Once the device is reset, check again that your email sending/receiving is working.

Additional help: If the above methods do not help, try the following:

1. Remove and re-add your email account.
2. Repair your PST data file with Microsoft’s Inbox Repair Tool (SCANPST).
3. Repair your Office installation:
   • Navigate to Windows Control Panel-> Programs-> Programs and Features.
   • Find and select the MS Office application and click Change.
   • Then select Repair.

For further assistance, please call us on 059 335 000 or email us at info@neoserv.si.