Checked, Unchecked and Either Filters for Exchange Connection Management > User Mailbox Management

Hi,

For Exchange Integration, under Administration > E-mail and Documents > Exchange Server Integration > Connection Management > User Mailbox Management tab, the search filters include Checked, Not Checked and Either. Do they indicate if the mailbox is checked or not checked to enable synchronization, or else ? Also, I suppose the "Either" filter is same as either Checked or Not Checked radio box is checked, isn't it? Thanks a lot!