Last modified: July 23, 2011

Applies to: Outlook

Initiates the logoff process.

HRESULT TransportLogoff(
  ULONG ulFlags


[in] Reserved; must be zero.


The call succeeded and returned the expected value or values. If anything other than S_OK is returned, the provider is logged off.

The MAPI spooler calls the IXPLogon::TransportLogoff method to terminate a transport provider session for a particular user. Before calling TransportLogoff, the MAPI spooler discards any data about supported messaging address types for this session passed in the IXPLogon::AddressTypes method.

The transport provider should be prepared to accept a call to TransportLogoff at any time. If a message is in process, the provider should stop the sending process.

The transport provider should release all resources allocated for its current session. If it has allocated any memory for this session with the MAPIAllocateBuffer function, it should free the memory by using the MAPIFreeBuffer function. Any memory allocated by the transport provider to satisfy calls to the IXPLogon::AddressTypes method can be safely released at this time.

Usually, on completing a TransportLogoff call, a provider should first invalidate its logon object by calling the IMAPISupport::MakeInvalid method and then release its support object. The provider's implementation of TransportLogoff should release the support object last, because when the support object is released, the MAPI spooler can also release the provider object itself.

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