Why list members cannot receive message sent to a "xxx-list-request@lists.ust.hk"?

Please note that a mailing list abc-list@lists.ust.hk is different from abc-list-request@lists.ust.hk. The former one contains all the list members while the later one with the suffix “-request” (after abc-list) is only used by the system and is for user who would like to subscribe to that particular mailing list.

In case you have sent message to a list with the suffix “-request” (e.g. abc-list-request@lists.ust.hk), none of the list members (e.g. abc-list@lists.ust.hk) can receive your message and you are required to resend the message again to the correct list (email address).

Remember NOT to choose list names with the "-request" suffix when you want to send message to a mailing list.