If you see Outlook error 0x80042109 on your Windows 10 PC when trying to send emails through Outlook, this article can help you solve the problem. For some users, this error can be a serious problem because it prevents them from using the Outlook application. In this article, we have discussed the possible ways to solve this problem.

Outlook cannot connect to your outgoing mail server (SMTP). If you keep getting this message, contact your server administrator or Internet Service Provider (ISP). Error 0x80042109.

Check your Internet connection

Slower or lower network performance may be the main reason for these Outlook errors. So, first of all, check your network connection properly and make sure that the connection speed is good and working properly. If possible, change your Internet Service Provider (ISP) Internet connection and see if that solves the problems.

Reinstall Outlook on your computer

The error can also occur because Outlook is not installed correctly. So reinstall it on your computer.

To do this, you must first uninstall the software and then reinstall it. After reinstalling the software, try sending the email again. If it was sent successfully, it means that the failure was due to an incomplete installation.

However, if the error persists, it is recommended that you restore the points by going to the “System Restore” option and selecting the “Restore my computer to an earlier point in time” option. This will undo the changes.

Check your email settings

Check your email settings to see if SMTP is selected for your outgoing email server. If not, this may be the cause of the problem. To check your email settings and select an option, you need to do the following:

Install any pending Windows updates

Windows 10 Update KB4507453 Interrupts SFC-Scan Command

Remove unnecessary files using the command line


When working in Outlook, Microsoft Outlook error 0x80042109 can appear for several reasons. Whatever the cause, the solutions presented in this article are sure to help you fix the error. We recommend you to use Stellar Outlook Repair to fix this error. The advanced recovery tool can repair all corrupted Outlook files.