Where can a user find the post that was rejected by the moderator?

But that’s not a solution.
A better way would be to let the user to change smth in the post. In this case we simply should keep the post inactive but dismiss it from the moderation tab.

A moderator can send the user a message what to fix in the post. This way the idea of the moderation process is fully realized.

But when we simply delete the post we damage the reputation of the site. Please, think of it from this point.