how to update email server on dba_network_acls

My email server has been changed.

I got errors during sent emails from my 11g database.

smtp_out_server has change to new email server IP.

Testing email can send out without any problem

When I ran my procedure, DOCADMIN.PK_NOTIFICATION1, I got,

ORA-06512: at "SYS.UTL_MAIL", line 662

ORA-06512: at "SYS.UTL_MAIL", line 679

ORA-06512: at "DOCADMIN.PK_NOTIFICATION1", line 312

ORA-29278: SMTP transient error: 421 Service not available"

select * FROM dba_network_acls;

I got old email server ip

Please help. Thanks

Lily W