Most system ready-templates will be locked by default to only allow single column items to be added. This prevents formatting issues to the layout of the message and provides the best compatibility across mobile devices.
However, if you would like to add additional columns to your message, you can do so by adjusting this locking mechanism on your message.
This can easily be done by:
- Editing the message in question
- Selecting the Design tab in the right panel of the email editor
- Ticking the check-box to "Enable multi-column layout" found under the Email Settings menu
Once done, you will once again have complete control over changing your template layout.