A referral in Public Folder-land is when the client (eg Outlook, and the end-user) request a public folder which is not homed on the information store that Outlook is connected to.. it’s home public folder information store.
This referral happens automatically. The referral is a redirection to a public folder server/information store which does contain a replica of the folder which is being requested.
The issue here is when that ‘user’ is the Vault Service Account, and, that is operating unlike a regular end-user as it is going to be getting these referrals during archiving runs, with multiple threads, and heavy amounts of activity to the public folders.
When the Public Folder Archiving Task starts to process targets it checks to see whether a referral/redirection is going to take place, and if it is going to, then the following is logged:
Event Type: Warning
Event Source: Enterprise Vault
Event Category: Public Folder Task
Event ID: 3369
Public folder redirection has been detected. This configuration can adversely affect performance and reliability. This redirection could be either of the following:
-The mailbox that is being used to connect to Exchange Server is being redirected to another Exchange Server.
-The Public Folder store is not homed locally on the target Exchange Server
Exchange Server: MAPLE
Public Folder Task: Public Folder Task For MAPLE
Redirected to Server: EXCH2003
This was first discovered with Enterprise Vault 2007. The limits observed during the implementation of the event log warning was that you were allowed 5 referrals in 10 seconds. The sixth connection would result in MAPI_E_NETWORK_FAILURE.