Optimum Minimum Size For Participation
By default, the minimum size setting for an attachment to make use of DAOS is 4096 bytes (or 64000 (64K) in later versions). I would recommend using10485760(10 MB) in this field. BUT to find the best option you could use the DAOS Estimator. If you use for example 64000 (64K) then every small jpg picture from every email is collected in your DAOS folder, which can result in a large amount of files and therefore in bad server performance.