Distribution Lists are not shared across accounts, but live at the account level.
With Distribution Lists, you can sort and save groups of users and non-users to speed up sharing.
Selecting the Contacts icon from the left menu bar and then click the Plus icon at the top of the Distribution List panel.
This will open the Distribution Lists Wizard.
Enter a list of recipients, hitting the 'enter' key after manually entering external email addresses. Give the list a name, and save.
The Distribution List will now appear in the panel.
You can drag and drop assets over a Distribution List to send a Quicklink to that list, as well as retrieve the list by hitting the 'down arrow' in any recipients field.