Michael,
if (I use the New Topic feature) is there (a copy of my post somewhere
in my Groups.io group that I sent the message to), (and if so) how can
I find it?
No there is not. Nor is there for replies you post via the group's Messages section. They only surface if approved to post in the group.
It would be nice if there were an equivalent of the Sent folder, say on your Subscription page. Failing that, or maybe in addition to it, it would also be nice if there were a BCC me checkbox in both places (New Topic and Reply). It is possible that one or both ideas have been discussed in beta:
Shal
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