Because of Google's downtime recently, emails sent to Gmail and Google Workspace (formerly G Suite) email addresses while they were down returned a hard bounce status.
Hard bounce in turn means that your contacts were unsubscribed since the email address was thought to be non-existent. This also means you'll also see a drop in open rates for emails sent during the outage period.
This doesn't happen to us only, it happens to every other ESP (email service provider) as well.
We are currently working on restoring your contacts that were unsubscribed because of this issue.
