How do I reply to a lead?

When you click on an Open Lead, you can quickly reply to that lead by clicking the Reply button and clicking Send Email once you've finished crafting your response. 

If your recipient responds back, it will automatically re-open the lead so it will show in your Lead Catcher queue again.

If you look at your lead after clicking Send Email, you'll see your reply show up as a One Off Send. This simply means it was an email you manually sent and not part of a campaign sequence.