Brazil,  
My son is working on an email newsletter list and autoresponders. Anybody know of a good open-source option?

#open-source #newsletters
  
They do indeed.
  
Mautic and odoo have features.
Our people use an MS desktop program called e-campaign. Its on a vps, so remotely accessible even using a mobile phone. It's more cost effective. When using mailchimp, etc, the costs become excessive when sending millions per month.
  
Taking a look at those, thanks. Though it looks at first hand to be more than we might could handle.