objectionable content rule

Learn how to block emails that include any spam related keywords. However, if that were too aggressive as a means of filtering, you would need to suggest some specific pattern you've detected in the spam emails we can use to trigger the rejections, as I feel that blocking any keyword related to invoicing might be excessive.

You can set up an objectionable content rule by following these steps: 

1) Access admin.google.com

2) Click on Apps > GSuite > Gmail > Advanced settings

3) Locate the section called Objectionable content and click on Configure

4) Enter a descriptive title for the rule

5) Select Inbound as Email messages to affect

6) Enable the box Custom objectionable words and click on Add

7) Add the word that will trigger the rejection, like Purchase Order or Invoice. Please note that escape characters like / or : can't be used.

8) Select the action that'll be applied to the message (Reject)

9) Click on Add setting and confirm with Save

Bear in mind it can take up to one hour for the new setting to apply. You can get more information about objectionable content in the following article of our Help Center https://support.google.com/a/answer/1346936?hl=en.