返回或设置收件人的跟踪状态。OlTrackingStatus 常量，可读写。
| OlTrackingStatus 可为以下 OlTrackingStatus 常量之一。 |
| olTrackingDelivered |
| olTrackingNone |
| olTrackingNotDelivered |
| olTrackingNotRead |
| olTrackingRead |
| olTrackingRecallFailure |
| olTrackingRecallSuccess |
| olTrackingReplied |
expression.TrackingStatus
expression 必选。该表达式返回 Recipient 对象。