Thanks Vipul.I did a test in ACS using same reply-to and error address, sent email and replied with "unsubscribe" in the subject but the profile is not blacklisted. Also reached out to deliverability team and they are not aware it is possible to blacklist if someone replies with 'unsubscribe' in subject/body.Just wanted to confirm writing inbound rules is not possible to process unsubscribe requests in ACS?

Hi Vipul,I'm also looking for similar functionality for client, reviewed these links. Campaign Standard - Managing deliverability https://docs.campaign.adobe.com/doc/AC/en/technicalResources/Technotes/AdobeCampaign_Deliverability_Mx_Inbounce.pdfCan you please provide more insight on how to write MX inbound management rules?Thanks,Mahesh