ExchangeWP Add-Ons: MailChimp
This article covers MailChimp.
Step by Step Instructions
To use the MailChimp add on, you'll first need to create an account and a list at MailChimp.com.
On your site, you'll install the ExchangeWP MailChimp add-on as you would any other plugin on your site. To enable/disable the MailChimp add-on, you'll go into ExchangeWP > Add-ons.
Once installed and enabled, you'll go to the settings (the gear symbol next to the Enabled button on the Add-ons page).
You'll need to go into your MailChimp settings and then Extras > API Keys to create the key you'll use on this site.
There, you'll find a button to create an API Key then copy that key.
Back in your MailChimp add-on settings in ExchangeWP, you'll paste your API key in. Entering your API key will populate the MailChimp List drop down menu. If you have multiple lists, they will allow show in the drop down menu.
Then, if you'd like, you can change your Sign up Label text. You can also check whether or not you'd like the opt-in option to show or if customers are automatically added. And lastly, you can select whether or not your customers have to double opt-in for your email.