EWS Managed API and Store EntryID of item

I want to retrieve the Store EntryID (PR_STORE_ENTRYID) of an item through EWS Managed API in hexadecimal form.

I manage to retrieve the binary using an ExtendedPropertyDefinition with tag 0x0FFB, convert using Convert.ToBase64String, and then convert EWS ConertId / BitConverter.ToString (there is probably an easier way).开发者_运维百科

I retrieve Store EntryId for same item through MFCMAPI tool for comparison. What I end up with through the EWS way is the last part of the Store EntryID.

Am I doing something wrong?

I never played with id conversion but did you try something like described here? http://msdn.microsoft.com/en-us/library/gg274397(v=EXCHG.80).aspx