For folks still using #MailChimp or ConstantContact, etc. & finding it insecure (https://www.bleepingcomputer.com/news/security/mailchimp-discloses-new-breach-after-employees-got-hacked/) or crazy expensive, we've been using #Mautic (https://mautic.com - acquired by #Aquia, the company behind the #Drupal project) for several years now. It's #FOSS and we moved from the SaaS version (cost similar to Mailchimp) to self-hosted, resulting in a 97% cost savings (yes we're paying %3 of the SaaS cost without per-contact costs). Full story here: https://www.irrodl.org/index.php/irrodl/article/view/5763/5600