CloudM Migrate uses native APIs to access the IBM Domino mailbox data and is not affected by whether DAOS service is running or not.
Lotus Domino Object and Attachment Service (DAOS), a feature introduced in Lotus Domino 8.5.0, is designed for saving disk space. DAOS extracts attachments from email messages and stores them in a separate location, replacing them with a reference to the stored data. DAOS is completely transparent to C API calls, agents, and LotusScript.
When migrating from IBM Domino to Office 365 and Exchange, make sure that the Lotus Notes mailbox size (mail file size + attachments stored in DAOS) does not exceed maximum mailbox size for Office 365 or Exchange prior to migration.