Execute Shell Command for sending mail from PL/SQL - oracle

Question

We are forced to use mailx command from PL/SQL for sending mail.
Actually I have the generic script with me, but I am not sure how to execute directly in the PL/SQL code.
The code we have is
(echo "$mailbody" uuencode $ZIP_FILE $ZIP_FILE) | mailx -m -s "subject" -r " " "$mail_to_address"

Answer 1

Obviously you've explained that Oracle has built-in support through UTL_MAIL and it's foolhardy to not use the functionality your organization has already paid for :)
" I am not sure how to execute directly in the PL/SQL code"
You can't run OS commands directly from PL/SQL. However...
Since Oracle 10g, DBMS_SCHEDULER has allowed us to call host programs. CREATE_PROGRAM() where program_type => 'EXECUTABLE'. The scheduler approach would be the best approach if you want to have a background job which polls for notifications and then sends batches of emails. Frankly the best intro the DBMS_SCHEDULER is Tim Hall's articles on Oracle-Base.
But if you need on-demand execution of calls then the approach you need is a Java Stored Procedure which uses a Java Command object to run host calls. There can be political issues with this, because some DBAs are suspicious of Java, but it's supported. Here's an Oracle White Paper which explains how to go about it.

Answer 2

You can send email from a PL/SQL procedure without invoking an OS command like mailx. Some examples are here:
http://www.orafaq.com/wiki/Send_mail_from_PL/SQL
Example code from one of the examples:
DECLARE
v_From VARCHAR2(80) := 'oracle#mycompany.com';
v_Recipient VARCHAR2(80) := 'test#mycompany.com';
v_Subject VARCHAR2(80) := 'test subject';
v_Mail_Host VARCHAR2(30) := 'mail.mycompany.com';
v_Mail_Conn utl_smtp.Connection;
crlf VARCHAR2(2) := chr(13)||chr(10);
BEGIN
v_Mail_Conn := utl_smtp.Open_Connection(v_Mail_Host, 25);
utl_smtp.Helo(v_Mail_Conn, v_Mail_Host);
utl_smtp.Mail(v_Mail_Conn, v_From);
utl_smtp.Rcpt(v_Mail_Conn, v_Recipient);
utl_smtp.Data(v_Mail_Conn,
'Date: ' || to_char(sysdate, 'Dy, DD Mon YYYY hh24:mi:ss') || crlf ||
'From: ' || v_From || crlf ||
'Subject: '|| v_Subject || crlf ||
'To: ' || v_Recipient || crlf ||
crlf ||
'some message text'|| crlf || -- Message body
'more message text'|| crlf
);
utl_smtp.Quit(v_mail_conn);
EXCEPTION
WHEN utl_smtp.Transient_Error OR utl_smtp.Permanent_Error then
raise_application_error(-20000, 'Unable to send mail', TRUE);
END;
/