In some situations, Outlook users might come across the following error message outlook cannot connect to outgoing SMTP server:
Task ‘account@domain.com – Sending’ reported error (0x80042109):Outlook cannot connect to your outgoing (SMTP) e-mail server.
A suggestion usually follows the error message, and it asks the user to contact the ISP (Internet Service Provider) or server administrator if the same error message continues to appear on the computer screen.
The causes for the occurrence of the Outlook error under discussion might be one of the following:
Wrong configuration settings on Outlook could result in the error. An incorrectly-spelled mail server name or a wrong port setting might lead to connectivity issues so that the error outlook cannot connect to outgoing SMTP server is occurred. These will, in turn, cause the error to pop up.
In case you can connect to the mail server IP and the ports for POP and SMTP, then the problem is not related to connectivity. It means that the 0x80042109 error is due to your Outlook settings.
Steps to fix the Outlook error: