Display Sender Name in oracle apex mail

You can display send name using oracle apex_email

 apex_mail.send(
                p_from => "Sender Display Name"<fromemailaddress>

don't enter space after the sender display name double quotes(") and from email address less than symbol (<)

List users with DBA privilege

Which users having dba provilege assigned, query dba_role_privs in the SYS schema

SQL>  select * from dba_role_privs where granted_role='DBA';