PostOffice Relay
The PostOffice Relay is an email transport method in which email is registered in the Rational® ClearQuest® database, which prevents loss of email messages.
This transport type is implemented by using the Rational® ClearQuest® EmailRelay service. With the PostOffice Relay, email messages are stored in the Rational® ClearQuest® database. Therefore, they cannot be lost even if the relay service goes offline. When the relay service restarts, the service resumes where it stopped, and delivers all the outstanding emails.
This illustration depicts how EmailRelay in PostOffice Relay mode is architected.

The Rational® ClearQuest® Web server communicate with the Rational® ClearQuest® EmailRelay server using PostOffice Relay. The Rational® ClearQuest® Web client communicates to the Rational® ClearQuest® Web server through a browser. The EmailRelay sever communicates through the optional firewall to the email server.