I am pleased with a campaign. How can I keep working with the design?

If you are happy with the newsletter you sent, and want to send more just like it, the most practical option is to copy the newsletter for a subsequent similar campaign.

You can do this on the Campaigns → Browse page in your account. Click 'Copy' next to the sent newsletter.

By copying, you will create a new campaign, for which you can quickly run through the Six Step Guide. 

Your newsletter's design will then be identical to the one you copied. In Step 4, you can insert texts and images into your new newsletter. If you want to, you can further edit the newsletter's design in this step.