EntryID unique?

[Andreas Schachl]

Hello!

Ive got a question concerning the EntryID of an object:

Is every EntryID unique and wont be used even if the object was deleted?

For example:
object a - entryid 1
object a is deleted
object b is created and gets entryid 1

So is every EntryID unique for any time?

Furthermore I wonder if there is a difference between using EntryIDs
with Outlook alone or in connection with Exchange Server?

Thanks in advance!

Andreas

 

[Ken Slovak - [MVP - Outlook]]

Yes, it should be unique. EntryID's will change in an Exchange mailbox if
the item is moved or deleted. They don't change in a PST file. That's
transport dependent. Exchange also provides short-term and long-term
EntryID's, for a PST file you only get a long-term EntryID. So when using a
MAPI table for example you would check for both EntryID's to make sure you
get a valid result.

 

[Andreas Schachl]

Yes, it should be unique. EntryID's will change in an Exchange mailbox if
the item is moved or deleted. They don't change in a PST file. That's
transport dependent. Exchange also provides short-term and long-term
EntryID's, for a PST file you only get a long-term EntryID. So when using a
MAPI table for example you would check for both EntryID's to make sure you
get a valid result.

Thanks!

Does this mean that there is no way to "track" an item from another
application using its EntryID since if it is moved or deleted I wont
find it under its EntryID?

Thanks in advance!

 

[Ken Slovak - [MVP - Outlook]]

Correct. I usually store the original entry id in a user defined field and
check on that so if EntryID changes my field remains the same.