Can't send e-mails from Outlook 2016

When I try to send e-mails from Outlook 2016, I get the following error message:

The operation failed. The messaging interfaces have returned an unknown error. If the problem persists, restart Outlook.

I have restarted Outlook and even rebooted my computer, but the problem still persists. I can receive and read e-mails, but the problem, which just started happening recently, is in sending them.

Does anyone have any idea how to fix this so I can send e-mails again?

Solution 1:

According to your description, I noticed that your problem is similar to this known problem: The operation failed error when you send email messages in Outlook. Please check if your case is consistent with the symptoms mentioned in the article.

If so, it is recommended that you try to configure the two accounts separately in different profiles according to the resolution mentioned in the article.

Hope to help you!