QMailMessageListModel class not sending most of it signals

Following documentation for QMailMessageListModel class, creating a new instance without parameters and without setting any with QMailMessageModelBase::setKey(const QMailMessageKey & key) nor setting the ignore flag with QMailMessageModelBase::setIgnoreMailStoreUpdates(bool ignore), the model:

"By default, the model will match all messages in the database, and display them in the order they were submitted, and mail store updates are not ignored."

I've attached a simple example that shows how, at least, the follwing signals are not being emitted by this object when they should:

• QMailMessageModelBase::modelChanged()
• QAbstractItemModel::dataChanged(const QModelIndex & topLeft, const QModelIndex & bottomRight)
• QAbstractItemModel::modelReset()
• QAbstractItemModel::rowsInserted(const QModelIndex & parent, int start, int end)

Maybe I'm doing something wrong so, please, comment.