wp.insider

affmngr

This addon allows you to specify a MailChimp list name in the addon settings. When affiliates join your site, they get signed up to the specified MailChimp list automatically.
This addon requires the <a href="https://wordpress.org/plugins/affiliates-manager/" rel="ugc">Affiliates Manager Plugin</a>.
After you install this addon, go to the MailChimp settings interface and specify your API Key and the MailChimp list name.
Read the following page for step by step usage documentation: 
http://wpaffiliatemanager.com/signup-affiliates-mailchimp-list/

Affiliates Manager MailChimp Integration

An addon for the Affiliates Manager plugin to signup the affiliates to your MailChimp list

frenchsquared

Comment-Emailer allows you to customize the email wordpress automatically 
sends when a new comment, pingback or trackback has been approved. 
With Commented-Emailer you can change the sending email address, message body, 
and enable or disable all of the default options such as including the authors 
name, ipaddress, website, comment or reply to address.
After installation you will have a new tab under settings that 
will give you access to change just about every access of your 
auto generated emails. Just make sure you enable Commented-Emailer

Comment-Emailer

Comment-Emailer allows you to customize the email wordpress automatically sends when a new comment, pingback or trackback has been approved.

Affiliates Manager MailChimp Integration vs Comment-Emailer