In the help message for the 'Default Recepients' options of the 'Extended E-mail Notification' plugin found in the Jenkins global configuration, one can find the not so clear statement:
Customize the default recipient list of the email notifications. The plugin will use this list if none is overridden in the project configuration. You may use the $DEFAULT_RECIPIENTS token in projects to include this default list, as well as add new addresses at the project level. To CC or BCC someone instead of putting them in the To list, add cc: or bcc: before the email address (e.g., cc:someone@example.com, bcc:bob@example.com).
Taking a best guess how this could work I gave the following a try - and it worked:
emailext body: '', to: '$DEFAULT_RECIPIENTS', subject: 'To default recepient list'
Be careful not to use double quotes for the to:
argument as groovy would jump in and try to replace it with the value of a variable called DEFAULT_RECIPIENTS
.
What apparently doesn't work is leaving out the to:
arguments. It'll just say that the list of recipients is empty.