For us to dive into the exact root cause, I'd suggest submitting a ticket to Adobe Campaign Support since we'll likely need to review your Campaign instance and the recipients that are bouncing.
That said allow me to provide some generic info around the messages you are experiencing below:
Momen_Code10_InvalidRecipient Invalid recipient typically indicates that either the address or the domain is typo'd or doesn't exist and thus the address cannot be sent to. This is a hard bounce error message.
Momen_Code40_GenericBounce Generic Bounce means that the receiving domain sent us a failure response that did not match any known rule. This is listed as a soft bounce. In order to address an error like this, you would need to reach out to the recipient's email provider to understand what the failure was.
Momen_Code54_RelayDenied Email was blocked by the receiving domain because relaying is not allowed. If your instance uses a relay, some domains may not accept your deliveries. This would also be considered a hard bounce.
Thanks so much for your reply, as it is very useful indeed. Really grateful for your kind sharing on this knowledge.
As my company has just started using Adobe campaign in the past month, I would need my IT to check whether or not the backend setting is correct. This is because the domain of those ‘affected’ records are coming from those proper/ famous one. So, it makes me feel puzzled for why so many bounce case is happening. And if necessary, i would surely raise the ticket to Adobe Support.
No worries at all. Your MX/Domain management can matter with bounces though that is typically in regards to a message being throttled or being queued up as the max amount of messages per-hour for a specific domain gets hit.
That said, these configurations are typically custom and configured during the application implementation process, either by an Adobe Deliverability consultant or by our clients so they tend to vary a bit. From what I'm seeing, it doesn't look like anything entirely out of the ordinary, but I'd highly recommend pulling in an Adobe Deliverability consultant as this is their realm of expertise.