Emails that have been created by a machine are generally less trustworthy than an email that has been sent by a person - this is because in most cases, this is because dangerous emails are often sent by a machine. It's generally simple to determine whether you should take note of this warning, such as seeing if there are any additional risks identified by the other indicators and understanding the common scenarios where you might receive emails that are machine-generated that do not pose any threat, such as newsletters and promotional emails.
An email that is written like it has been sent by a person and might even be asking you to carry out an action, is where you might want to pay more attention to this warning. In most cases, it will be an amber indicator that is generally presented with a machine-generated email. Amber indicators indicate that there is some (low) risk identified with the email to be wary of, but that it's most likely business as usual.
OnINBOX takes steps to alleviate 'false positives' in this situation. It does not present machine-generated email warnings for the top 5,000 domains (excluding any email address providers like gmail.com) as, generally, authenticated machine-generated emails from domains of highly reputable companies such as microsoft.com and google.com are of no concern.