Users encounter an error message after clicking a custom merge button used to send emails via Doc/Mail Merge and assume the email failed, leading them to click the button again. However, the email is actually sent successfully each time, and the error message does not provide any indication of this.
This lack of clarity creates confusion and results in unintended duplicate emails being sent. Users have no way to confirm whether the action was successful when an error appears, which impacts user confidence and can lead to communication issues with recipients.
Adding a clear note in the error message indicating that the email was still sent successfully would help prevent duplicate sends and improve overall user experience.