I need to add a batch of imap DataSources to my pilot group, so that they get their current mail inside of the zimbra pilot server. Here is what I have been testing for adding it:

./zmprov cds user@zimbra.domain.com imap name zimbraDataSourceEmailAddress user@domain.com zimbraDataSourceEnabled TRUE zimbraDataSourceHost domain zimbraDataSourceUsername user zimbraPrefFromAddress user@zimbra.domain.com zimbraPrefFromDisplay 'User Name' zimbraDataSourceConnectionType cleartext
here is the error I get:
ERROR: service.INVALID_REQUEST (invalid request: createDataSource invalid schema change: [LDAP: error code 65 - object class 'zimbraImapDataSource' requires attribute 'zimbraDataSourceFolderId'])
I understand that I need to add this attribute, but my question is... How do I know what the next id number in the sequence? I don't want to apply an id number that is already in use. Is there away that this will automatically apply the next number in the sequence?
Suggestions? Thx!