Adding Owner for Distribution List

See "What is Owner for Distribution List?"

Log in to the console, Click "Distribution List" on the dashboard menu, and select the distribution list you want to add a new Owner by clicking the "Gear Icon."

Click "Owner" → "Add Owner"; 

Select and check the users you want to add Owner to a distribution list of members and click "ADD."

See summaries of how many Owners have been added to the distribution list on the distribution list dashboard.

Once the users already added to the owner of the distribution list, the users can manage the distribution list from their mailbox account, Besides adding and deleting members, distribution list properties that owners can configure include the following:

• Marking the list as private so it is hidden in the Global Address List
• Managing who can send messages to the list
• Setting a member subscription policy
• Adding additional owners 

See " Managing Distribution Lists from Mailbox Account"