A direct mail manager is a user granted permissions to use the direct mail sending feature.
Your admin should set up this feature.
The feature will only appear if the direct mail manager is using the system in Japanese.
Access the settings from ① Admin settings → ② Direct mail manager settings, and set ③ Direct mail manager, then click ④ Add.
The added direct mail manager will appear in the list.
Added users can immediately use the sending feature.
Direct mail managers can also be deleted from the list.