EWA Full text searching
Users can perform full-text searches on messages in their mailboxes.
Unlike the Find function, which only looks at some of the headers, the Search inspects the entire message body too. Searches can be run on a single folder, or on an entire mailbox.
Webmail Administrators can give Users access to the full Archiving search and recovery features of Mailtraq. See Webmail Administration.
Read more about Archiving here.
Naturally this can be a CPU-intensive function, so it may be disabled. Administrators can also set a millisecond timeout to prevent server overload, and may want to consider using a multiple-CPU server if this feature is expected to be used significantly.