Mass Mail Christmas Email Template + supported in Odoo v10, v11, v12
Find duplicate emails and delete in the mailing list
Know and track (un)subscription reasons, GDPR compliant
Use the QWeb templating mechanism for emails
Copy tracking fields from leads to partners
Enforces 1 registration per partner and event
Avoids duplicate mailing lists and contacts
Disable mass mailing to partners by default (opt-out)
Show additional social icons in Mass Mailing snippet