Prospects are not moving to sent status in campaign

Hello, 

I created connected campaign and added an automation rule to match tags from prospects to assign them to different campaigns. Now, when prospects are added they are getting assigned to the correct campaigns based on tag and automation rule, and their status changes to lead. But now, their status is not changing from lead to sent in the campaign. Any additional rules are required to send the emails from the campaign or that will happen when prospects are converted to leads?

Any help is appreciated, thank you.