Hello,
Have you recently created or upgraded your Google account to a Business or EDU domain? Users have reported this issue of emails being rejected in connection with recently upgraded or newly created GSuite Business or Edu accounts. These "new" Gsuite accounts can be subject to enhanced Google spam filters. Basically, Google filters need time to confirm that your Gmail account was not purely created to spam others, I don't know an exact timeframe for when this is determined by Google but most users report that within the first billing cycle the issue is resolved.
Another reason you may be seeing these rejection notifications is if they are being blocked from within your own network, it is possible your domain's email service is labeling the Autocrat generated emails as spam and blocking their delivery. Depending on the email security service used (Mimecast, Barracuda etc), there might be more information you can acquire on what they label as spam and if there are steps you can take to resolve this issue. Apologies that we can not provide specific steps for you as every email service provider and security gateway is different.
Hope something here is helpful.