The IMAPIFormMgr::IsInConflict method determines whether a form can handle its own message conflicts. A message is in conflict if it has been simultaneously edited by more than one user. This can happen to messages in public folders.
HRESULT IsInConflict(
ULONG ulMessageFlags,
ULONG ulMessageStatus,
LPCSTR szMessageClass
LPMAPIFOLDER pFolderFocus
);
Form viewers call the IMAPIFormMgr::IsInConflict method to discover if a particular form does not handle its own message conflicts. IsInConflict checks the bitmasks in the ulMessageFlags and ulMessageStatus parameters for the presence of a conflict flag. If a conflict flag is set, IsInConflict resolves the message class passed in the szMessageClass parameter and returns S_OK if the form does not handle its own conflicts. IsInConflict returns S_FALSE if the form handles its own conflicts.
A form that does not handle its own conflicts must be launched using the IMAPIFormMgr::LoadForm method and cannot reuse an existing form object.
Client applications typically have to deal with conflicts when going from one message to the next or previous message in a folder. If a message is in conflict, but the form server for that message can handle conflicts, then the client application should execute its usual code for displaying the next or previous message. If the form server cannot handle conflicts, then the client application should proceed as if it was unaware of the message class of the next or previous message.
IMAPIFormAdviseSink::OnActivateNext, PR_MESSAGE_FLAGS, PR_MSG_STATUS