When using "CreateMsgRequest" and other SOAP calls that create items, is it possible to specify and "id" to use (and assume it will return an error if that id is already in use)?

I am playing around with the Sync protocol to try to sync accounts between two Zimbra servers, but I am noticing that they each have their own id's since there are gaps on the source server.. so when I do a SyncRequest, it says to delete folder X, that id doesn't match the same id on the second server. The only way I have found so far is to have a metadata file stored off that keeps track of the mapping of id's between servers, and it's rather annoying and is adding a bunch of extra overhead.