Basically your post is already “posted” there. Anyone with a mastodon account on an instance that federates can see it. They could either paste on their mastodon search interface the url to this post and see it appear as a mastodon message. They could then reply on mastodon and it would show for you here on your lemmy instance.

They could also follow your account on mastodon or a community just as if you were a mastodon user and then see your posts on their timeline.

Not quite. Lemmy isn’t set up to make microblog posts, but mastodon users can still see community posts and comments and reply.

If a mastodon user comments on AA Lemmy post, and a Lemmy user replies, it will be delivered to the mastodon user. I’ve not tried posting to a mastodon user directly though.

Paging myself at @baronvonj@mas.to to see if this works.