That's actually an incredibly annoying fallout of gmail's deduplication that cannot be disabled. I believe gmail de-duplicates your list echo because it sees a copy in your sent folder. I wish it could be disabled :-/
If list owners wanted this to be a feature, you could configure it on a list basis, at least in mailman. However nobody does, because it's incredibly annoying :-)
Agreed. Whenever I mail a list if I have an important message I have to ask someone if the message appeared or not. I can't verify by receiving my own copy. I use mail lists every day.
