Hi Naveen,
Looking at issue mentioned, I think your ELM workflow customizing is missing.
Go to SPRO->CRM->Marketing->External List Management
1. Execute - Implement Workflow Customizing - Activate the event linkage and make it general task if no agents required for processing.
2. Read the HELP of this node as there are some additional workflows/tasks to be activated as per requirement.
Also check if you have assigned the user parameter CRM_DEBUG_CODE = MKTLIST in SU3 transaction. If assigned then remove it and then test again.
Regards,
Naresh