Odoo Marketing
The changes to the Odoo Marketing apps in Odoo 15 are modest. However, many technical improvements have been made for sending emails and SMS messages. These improvements also provide more insight into the analyses of sent messages.
You can find a few new features in Odoo 15 below.
Social Marketing
Instagram and YouTube have been added as possible social media channels on which a post or video can be published.

Website building blocks are now available for marketing campaigns
All building blocks available for the website can now also be used to create an email marketing campaign. So you have many more options for the design of your email campaign.

Start with an empty template
A new empty template has been added so that you can build a layout from scratch with new building blocks.
More selection options
The options for creating contact selections have been expanded with the ability to email contacts with a subscription.