Thank you, Brian. By continuing to play around forwarding e-mail with graphic
attachments, varying the forwarding choices, following directions!, etc., I found the root of
my problem!! Though it seems "unintuitive" to me, it's incredibly simple!
If I forward any message w/graphic(s) using the first forwarding option - "Edit or make changes to the messages before forwarding them" and I DON'T make any changes to the forwarded message - i.e., if I just leave the extra space above the forwarded text empty - the message is always duplicated in the message queue.
HOWEVER, if I do as the option instructs and write anything at all in the space above the forwarded text, the message - even with graphics - is not duplicated, appearing only once in the message queue as expected!
If I choose the second option to simply "bounce" the message, the message is NOT duplicated in the queue, either. I did not experiment with the third and fourth forwarding options as I would likely never use those.