Can I cancel a message I've sent?

Question

We are using iMQ to send a message that will invoke a translet. One of our
requirements is to be able to cancel translets and specific messages once a
message has been sent to the broker. For example, lets say three messages
are sent to a broker, message 1, message 2 and message 3. While all three
messages are sitting in the queue waiting for the client, we would like to
be able to cancel one of the messages prior to being sent to the client,
for example message 2. Once the client becomes available message 1 and
message 3 would be the only messages available. (We will also be
implementing point to point synchronous queues). So far this does not
appear possible. From what I have found the API's do not seem to support
this. Do you know if this can be done?

Answer 1

The JMS API does not allow the producer of a message to 'recall' the message.
The producer can set different priorities and expiration times on messages to
affect handling of the messages relative to other messages that the are
generated by the same producer.
Can you give more concrete examples of the contents of the 3 messages and why
you would want message #2 deleted?
You can acheive a somewhat equivalent behavior without the message actually
having to be explicitly deleted by setting different properties when they are
produced and having the client use selectors, in which case message 2 would
not be available to the receiving client and could eventually be expired (by
setting an expiration when it was produced) and thus be deleted from the
system.