This article addresses the file processing size limits of DLP.
By default, on a Detection Server, DLP will only process messages that are 30 MB or smaller. If the message is greater than 30 MB, Data Loss Prevention will not process the message.
On the endpoint DLP will only process a file that is less than 30 MB.
The one exception to this is with encapsulation formats (.zip, .z, .tar, .rar etc). In that case, DLP will extract the files and process them. Any file within the encapsulation that is greater than 30 MB will not be processed. Any file that is less than 30 MB will be processed.
The 30MB value can be increased, but there can be resource issues for increasing the size. Please see related article or contact Technical Support if this is necessary.