Not quite. Lemmy isn't set up to make microblog posts, but mastodon users can still see community posts and comments and reply.
Mastodon
Decentralised and open source social network.
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.
@baronvonj@lemmy.world
It does indeed work. So you can post directly to a mastodon user from a Lemmy post comments section.
@pineapplelover
How do I @ a user like you did?
@baronvonj@mas.to
Edit: hmm interesting that's cool
Will it? That’s pretty cool.
Narrator: It did.
Yes, but no.
If some user follows you or community it will get federated into mastodon. Otherwise you can't relly push the post into mastodon.
If you mention a Lemmy community in a post on Mastodon, it appears as a post in that community. Like this post on Mastodon: it also shows up in the Lemmy community "Linux", and many if the comments are from Lemmy users: https://social.edu.nl/@foxy/111937325118529631
I don't think you can do microblogging like on mbin, but I think you can directly write and reply to Mastodon users, and posts with hashtags should also be able to be found by Mastodon users if they look for them. I don't think Lemmy threads have a hashtag field like mbin either though, so you would have to manually type them out when making a new thread.