MailChimp is compatible with Weebly’s newsletter form. You can embed MailChimp code into the newsletter form so that those who subscribe will automatically be added to a list in MailChimp. To configure, follow the steps below.

In MailChimp:

1. Go to your MailChimp lists
2. Choose the list you want to hold the new subscriptions, then click the arrow next to Stats
3. Click Signup Forms in the drop-down list that appears
4. Next to Embedded forms, click Select
5. Edit the form options as you see fit
6. Copy the code under the Copy/paste onto your site header
7. Now go to your Weebly site

In Weebly:

1. Find Embed Code option at the bottom of the left sidebar and drag-and-drop it onto the live editor 
2. A box with the text “Click to set custom HTML” inside will appear. Click this box
3. A pop-up will appear. Click Edit Custom HTML within the pop-up
4. Paste your code into the box that appears, then click outside of the box

A MailChimp generated form will appear in your newsletter form. Information submitted here will be added to your list in MailChimp.