3.1.5.1.4 Checking Message Expiration

To control message lifetime, a message can contain a <TTrq> element in the <Msmq> element or the <expiresAt> element in the <properties> element. Both these elements are deserialized to the SRMPMessage.TimeToReachQueue attribute, with the <TTrq> element taking precedence, if it is present in the message. The protocol checks this value while sending a message, as specified in section 3.1.7.2.1; it is not checked while processing a received message.