In Adobe Campaign Classic, if bounces are no longer being forwarded, the appropriate process to check is the mta (Message Transfer Agent) process. The mta process is responsible for sending out messages and managing delivery status, which includes bounce handling. When email delivery encounters issues, it's the mta process that logs these bounces and processes them accordingly.
If bounces are not being processed as expected, there might be issues with the mta configuration, network connectivity, or email server responses. By checking the mta logs, a developer can troubleshoot and identify any errors or misconfigurations that may be preventing bounce notifications from being forwarded. Additionally, verifying the mta process is running smoothly is crucial for ensuring the entire delivery and bounce-back mechanism functions properly within the Adobe Campaign Classic environment.