Oracle cloud to exchange server connectivity?

[admin]

DB 12c ACL is deprecated and ACE should be used.

APEX email error,
ORA-24250: No supported authentication scheme found

BEGIN
DBMS_NETWORK_ACL_ADMIN.APPEND_HOST_ACE(
host => '*',
ace => xs$ace_type(privilege_list => xs$name_list('connect'),
principal_name => 'APEX_180100',
principal_type => xs_acl.ptype_db));
END;

https://docs.oracle.com/database/apex-1 ... HTMIG29487