Microsoft Viva is a Microsoft Portal that monitors your Microsoft Account and assist with reminders and possible follow ups to your emails. The email did not come from you directly, it came from firstname.lastname@example.org. This update is letting reminding Charity about an email sent from you through outlook previously. If she would like to stop receiving emails from Viva she can unsubscribe at the bottom of the email, but it is not originating from your account.
You should be able to stop these by hitting unsubscribe at the bottom. We have tested them, and it is indeed a safe link. If anyone else has the issue, you can tell them to do the same.