Executing an external procedure from an Oracle Job

We have a PL/SQL web application on the Oracle8i Enterprise Edition Release 8.1.7.4.0 within the Solaris 8 platform.

We are having errors while trying to execute a job in Oracle that references an external C procedure. The C program is fine, the procedure executes fine in TOAD but does not in SQL Plus or the Oracle job.

Is it technically possible to call external procedures (with IN OUT parameters) from within an Oracle job?

The error generated references, the tnsnames.ora and listener.ora files... the configuration of both of those files seems to be correct. Any ideas on how to resolve this?

Here is the generated error:

----

SQL> exec email_notice.EXPIRE_ACCOUNTS('USER123','U','N');
BEGIN email_notice.EXPIRE_ACCOUNTS('USER123,'U','N'); END;

*

ERROR at line 1:

ORA-28575: unable to open RPC connection to external procedure agent
ORA-06512: at "USERABC.PT", line 46
ORA-06512: at "USERABC.EMAIL_NOTICE", line 1180
ORA-06512: at line 1

Look at your listener.ora and tnsnames.ora. Do you see any messages in the listener.log?

There's tons of information on metalink.