Marketing Automation Lists are lists used exclusively on the Pro Marketer plan. These include not only CRM Lists, but also Marketing Lists.
CRM Lists are entire modules of records in SugarCRM. CRM Lists are imported to INBOX25 using Symsync.
Marketing Lists are lists contained within a CSV file (Excel spreadsheet, google spreadsheet, etc) that you can import using our Lists->Create new List tab.
You can use CRM Lists or Marketing Lists to map field types from Landing Pages and forms to. You can also select Marketing/CRM Lists when selecting targets for Automated Campaigns. You can also send Email Campaigns to CRM/Marketing Lists. CRM Lists are fully integrated with SugarCRM while Marketing Lists has no integration with SugarCRM.
In other words, Marketing Lists are in-platform lists. The integration with the list stays within the INBOX25 platform. Whereas CRM Lists are native in SugarCRM, and INBOX25 is simply pulling data from SugarCRM when requested by the system.