By John Missinne

McKee Foods

Collegedale, TN

Fun with SMTPFrom http://marcel.wanda.ch/Fun/SMTP “Hitchhiker’s Guide to SMTP”

Last known to work in April of 1996: % telnet mail.germany.eu.net smtp Trying 192.76.144.65 ... Connected to mail.germany.eu.net. Escape character is '^]'. 220-mail.Germany.EU.net - EUnet gateway to Germany 220 ESMTP spoken here EHLO nice.ethz.ch 250-mail.Germany.EU.net Hiya nice.ethz.ch [129.132.66.13], long time no see250-SIZE 20000000 250 HELP MAIL from: waldvogel@nice.ch SIZE=335 250 waldvogel@nice.ch... A real hoopy frood. [...] . 250 QAA01569 Message accepted for delivery RSET 250 Reset state: 38911 BASIC BYTES FREE. QUIT 221 So long, and thanks for all the fish.

Oracle Provides SMTP

From Oracle’s UTL_SMTP Package specification comments…

A SMTP connection is initiated by a call to open_connection, which returns a SMTP connection. After a connection is established, the following calls are required to send a mail:

helo() - identify the domain of the sender mail() - start a mail, specify the sender rcpt() - specify the recipient open_data() - start the mail body write_data() - write the mail body (multiple calls allowed) close_data() - close the mail body and send the mail

The SMTP connection is closed by calling quit().

UTL_SMTP ExampleFrom Oracle’s UTL_SMTP Package specification comments…

DECLARE c utl_smtp.connection;

PROCEDURE send_header(name IN VARCHAR2, header IN VARCHAR2) AS BEGIN utl_smtp.write_data(c, name || ': ' || header || utl_tcp.CRLF); END; BEGIN c := utl_smtp.open_connection('smtp-server.acme.com'); utl_smtp.helo(c, 'foo.com'); utl_smtp.mail(c, 'sender@foo.com'); utl_smtp.rcpt(c, 'recipient@foo.com'); utl_smtp.open_data(c); send_header('From', '"Sender" <sender@foo.com>'); send_header('To', '"Recipient" <recipient@foo.com>'); send_header('Subject', 'Hello'); utl_smtp.write_data(c, utl_tcp.CRLF || 'Hello, world!'); utl_smtp.close_data(c); utl_smtp.quit(c); EXCEPTION WHEN utl_smtp.transient_error OR utl_smtp.permanent_error THEN BEGIN utl_smtp.quit(c); EXCEPTION WHEN utl_smtp.transient_error OR utl_smtp.permanent_error THEN NULL; -- When the SMTP server is down or unavailable, we don't -- have a connection to the server. The quit call will -- raise an exception that we can ignore. END; raise_application_error(-20000, 'Failed to send mail due to the following error: ' || sqlerrm); END;

More complex Email?

Set Message Priority Send HTML Text Send Attachments A simple, common email send api.

Possible Email solutions

Metalink – Complex PL/SQL sample packages. I spent a lot of time trying to figure out the package instead of figuring out SMTP.

Ask Tom – Java Mail Client. The java was not trivial to install, was horribly slow, and then was still complicated to use.

Metalink – Simple UTL_TCP example. This simple UTL_TCP example showed a simple SMTP interaction including an attachment.

We took the simple UTL_TCP example, a Mime reference, and a little bit of LOB research and created MFC_Mail.

MFC_Mail (core program)vConn := utl_tcp.open_connection(cServer, 25); -- Establish Connection with Email Serverbb := utl_tcp.write_line(vConn, 'HELO '||cServer); -- Shake Hands with SMTPbb := utl_tcp.write_line(vConn, 'EHLO '||cServer); -- Shake Hands with ESMTP (Extended SMTP)bb := utl_tcp.write_line(vConn, 'MAIL FROM: '||vFrom); -- Specify SenderAddress(pTo); -- Call Internal procedure that Send RCPT Messages for all recipients in a comma separated listAddress(pCC); -- Call Internal procedure that Send RCPT Messages for all recipients in a comma separated listAddress(pBCC); -- Call Internal procedure that Send RCPT Messages for all recipients in a comma separated listbb := utl_tcp.write_line(vConn, 'DATA'); -- Start Body of Emailbb := utl_tcp.write_line(vConn, 'Date: '||to_char( sysdate,'dd Mon yy hh24:mi:ss')); -- Send MIME Timestampbb := utl_tcp.write_line(vConn, 'From: '||vFrom); -- Send MIME Frombb := utl_tcp.write_line(vConn, 'MIME-Version: 1.0'); -- Send MIME Versionbb := utl_tcp.write_line(vConn, 'To: '||pTo); -- Send MIME Address Infoif pCC is not null then bb := utl_tcp.write_line(vConn, 'Cc: '||pCC); end if; -- Send MIME CC Infoif pBCC is not null then bb := utl_tcp.write_line(vConn, 'Bcc: '||pBCC); end if; -- Send MIME BCC Infobb := utl_tcp.write_line(vConn, 'Subject: '||pSubject); -- Send MIME Subjectif pImportance IN ('High', 'Medium', 'Low') then -- Set Importance bb := utl_tcp.write_line(vConn, 'Importance: '||pImportance);end if;bb := utl_tcp.write_line(vConn, 'X_Mailer: '||MailerSig); -- Send Mailer Signatureif pAttachments.Count = 0 then -- If Simple Mail, no attachments bb := utl_tcp.write_line(vConn, 'Content-Type: text/'||pBodyMType||nl); -- Set Content Type bb := utl_tcp.write_line(vConn, vBody); -- Send BodyElse -- Else bb := utl_tcp.write_line(vConn, 'Content-Type: '||Mixed||nl); -- Set Multipart Mixed Content Type bb := utl_tcp.write_line(vConn, '--'||MixBndry); -- Send Mixed Boundry if rCount > 0 then -- If Related Attachments exist bb := utl_tcp.write_line(vConn, 'Content-Type: '||Related||nl); -- Set Multipart Related Content Type bb := utl_tcp.write_line(vConn, '--'||RelBndry); -- Send Related Boudry end if; bb := utl_tcp.write_line(vConn, 'Content-Type: text/'||pBodyMType); -- Send Body bb := utl_tcp.write_line(vConn, vBody||nl); if rCount > 0 then SendAttachments(pAttachments, RelBndry, True); end if; -- If Related Attachments exist, send them SendAttachments(pAttachments, MixBndry, False); -- Send General (Non Related) Attachmentsend if;bb := utl_tcp.write_line(vConn, '.'); -- Send SMTP Closebb := utl_tcp.write_line(vConn, 'QUIT'); -- Say GoodbyeGetFeedback;utl_tcp.close_connection(vConn); -- Close Connection

MFC_Mail (Attachments)

SendAttachments -- Send Attachments in Attachment list, use the given boundary. procedure SendAttachments(pAttachments in Attachment_List, pBndry in varchar2, pRFlag Boolean default False) is aCtr integer; begin for aCtr in 1 .. pAttachments.count loop if NVL((lower(substr(pAttachments(aCtr).cType,1,1)) = 'r'),False) = pRFlag then bb := utl_tcp.write_line(vConn, '--'||pBndry); bb := utl_tcp.write_line(vConn, 'Content-Type: '||getMimeType(pAttachments(aCtr).AFName, pAttachments(aCtr).AType)); if pRFlag then bb := utl_tcp.write_line(vConn, 'Content-Disposition: inline; filename='||pAttachments(aCtr).AFName); bb := utl_tcp.write_line(vConn, 'Content-ID: <'||pAttachments(aCtr).AFName||'>'); else bb := utl_tcp.write_line(vConn, 'Content-Disposition: attachment; filename='||pAttachments(aCtr).AFName); end if; if pAttachments(aCtr).AType = 'T' then -- Text Attachment bb := utl_tcp.write_line(vConn); sendTextFile(pAttachments(aCtr).ADir, pAttachments(aCtr).AFName, pAttachments(aCtr).LFName); else -- Binary Attachment bb := utl_tcp.write_line(vConn, 'Content-Transfer-Encoding: base64'||nl); sendBinaryFile(pAttachments(aCtr).ADir, pAttachments(aCtr).AFName, pAttachments(aCtr).LFName); end if; bb := utl_tcp.write_line(vConn, nl); end if; end loop; bb := utl_tcp.write_line(vConn, '--'||pBndry||'--'||nl); -- Write Final Boundary end SendAttachments;

MFC_Mail (Text Attachment)

SendTextFile

procedure SendTextFile(pDir in varchar2, pFName in varchar2, pLName in varchar2 default NULL) is vFH utl_file.file_type; vLine varchar2(2000); vBuffer varchar2(4000); begin vFH := utl_file.fopen(pDir, NVL(pLName, pFName), 'r'); loop begin utl_file.get_line(vFH,vLine); vBuffer := vBuffer||vLine||nl; if length(vBuffer) > 2000 then bb := utl_tcp.write_line(vConn, vBuffer); vBuffer := ''; end if; exception when NO_DATA_FOUND then exit; end; end loop; if length(vBuffer) between 1 and 2000 then bb := utl_tcp.write_line(vConn, vBuffer); end if; utl_file.fclose(vFH); exception when others then if vForce then bb := utl_tcp.write_line(vConn, 'Error retrieving Attachment: '||pDir||'/'||NVL(pLName, pFName)); else raise; end if; end SendTextFile;

MFC_Mail (Binary Attachment)

SendBinaryFile

procedure SendBinaryFile(pDir in varchar2, pFName in varchar2, pLName in varchar2 default NULL) is vBF bfile; vOffset pls_integer := 1; vBlSize pls_integer := 57; -- 76 / 4 * 3 max for base64 encoding vBuffer raw(60); begin vBF := bfilename(pDir, NVL(pLName, pFName)); if dbms_lob.fileexists(vBF) = 1 then dbms_lob.fileopen(vBF); if dbms_lob.getlength(vBF) > 0 then loop begin dbms_lob.read(vBF, vBlSize, vOffset, vBuffer); bb:= utl_tcp.write_raw(vConn, utl_encode.base64_encode(vBuffer)); vOffset := vOffset + vBlSize; exception when NO_DATA_FOUND then exit; end; end loop; end if; dbms_lob.close(vBF); end if; exception when others then if vForce then bb := utl_tcp.write_line(vConn, 'Error retrieving Attachment: '||pDir||'/'||NVL(pLName, pFName)); else raise; end if; end SendBinaryFile;

MFC_Mail (some minor sub procedures)

Address-- Loops through a comma separated list and sends a RCPT TO message for each. procedure Address(pList in varchar2)is pL number := 1; pH number := 0; begin if pList is not null then while pH < length(pList) loop pH := instr(pList, ',',pL); if pH = 0 then pH := length(pList)+1; end if; bb := utl_tcp.write_line(vConn, 'RCPT TO: '||substr(pList, pL, pH - pL)); pL := pH + 1; end loop; end if; end Address;

GetFeedback

-- Get Feedback from Mail Server procedure GetFeedback is vFeedback varchar2(1000); vCtr integer; begin for vCtr in 1 .. 50 loop vFeedback := utl_tcp.get_line(vConn, TRUE); dbms_output.put_line(vFeedback); if instr(vFeedback, 'closing transmission channel') > 0 then exit; end if; end loop; exception when others then dbms_output.put_line('Error Retrieving Feedback from Mail Server'); end;

MFC_Mail.Send

-- Send Mail Procedure (MAIN). procedure Send(pTo in varchar2, -- Comma Delimited List pSubject in varchar2 default null, pBody in varchar2 default null, pCC in varchar2 default null, -- Comma Delimited List pBCC in varchar2 default null, -- Comma Delimited List pImportance in varchar2 default 'Normal', -- High, Normal, or Low pBodyMType in varchar2 default 'plain', -- either plain or html pAttachments in ATTACHMENT_LIST default Attachment_list(), pForce in varchar2 default 'FALSE', pFrom in varchar2 default null);

---------------------------------------------------------------------------------------------------

-- Function Used to send mail. -- Returns "Mail Sent" if the mail server accepts it and "Mail Send Failed" if it doesn't. function Send(pTo in varchar2, -- Comma Delimited List pSubject in varchar2 default null, pBody in varchar2 default null, pCC in varchar2 default null, -- Comma Delimited List pBCC in varchar2 default null, -- Comma Delimited List pImportance in varchar2 default 'Normal', -- High, Normal, or Low pBodyMType in varchar2 default 'plain', -- either plain or html pFrom in varchar2 default null) Return varchar2;

MFC_Mail (simple send methods)

exec MFC_Mail.send(/* TO */ 'Fred_Doe, Do_Re_Me', /* Subject */ 'Test Subject', /* Body */ 'Test Body...');

exec MFC_Mail.send(pTo => 'Fred_Doe, Do_Re_Me', pCC => 'Jane_Doe', pSubject => 'Test Subject', pBody => '<html> Test Body... ', pBodyType => 'html', pImportance => 'High');

select mfc_mail.send('Jane_Doe, Joe_Doe', 'Test Subject', 'Test Body....') from dual;

select mfc_mail.send('Jane_Doe, Joe_Doe', 'Test Subject', 'Test Body....', null, null, 'High', 'html') from dual;

MFC Mail (with attachments)

declare vBody varchar2(32767); vAttach Mfc.Mfc_Mail.Attachment_List := Mfc.Mfc_Mail.Attachment_List();begin vAttach.extend; vAttach(1).Atype := 'B'; -- Attachment Type: B: Binary or T: Text vAttach(1).Ctype := 'R'; -- Content Type: R: Related or M: Mixed vAttach(1).Afname := 'logo.gif'; -- Attachment Name shown in the Email vAttach(1).Adir := 'COMN_TEMP'; -- Attachment Directory vAttach.extend; vAttach(2).Atype := 'T'; vAttach(2).Afname := 'attachment1.txt'; vAttach(2).Adir := 'COMN_TEMP'; vBody := '<table width=800 border=1 bordercolor=black cellpadding=5 cellspacing=0>' || ' <tr><td width=266 align=center> <img src="cid:logo.gif" alt="<Our Logo>"> </td>' || ' <td width=266 vAlign="center"> Isn''t our logo nice.</td>' || ' </tr>' || '</table>'; Mfc.Mfc_Mail.Send(pTo => 'John_Missinne', pSubject => 'Example of HTML with inline Graphic and Attachment', pBody => Vbody, pBodymtype => 'html', pAttachments => Vattach, pForce => 'Yes', -- if pForce is Yes, then attachment failures will send anyway. pFrom => 'Oracle_Financials'); -- This line is not necessary since it is the default.end;

MFC Mail (output)

More Fun with SMTPFrom http://marcel.wanda.ch/Fun/SMTP “Forging Prevention”

% telnet mail.credit-suisse.com 25 Trying 194.209.128.98... Connected to mail.credit-suisse.com. Escape character is '^]'. 220 unigate1 SMTP ready, Who are you gonna pretend to be today? HELO blabla.microsoft 250 unigate1 Is thrilled beyond bladder control to meet blabla.microsoft MAIL FROM: sten@ergon.ch 250 sender is sten@ergon.ch, (yeah sure, it's probably forged) RCPT TO: gunterberg@ergon.ch 250 recipient bounce.me@credit-suisse.ch, I know them! they'll just *LOVE* to hear from you! DATA 354 OK, fire away. End with <CRLF>.<CRLF> From: sten@ergon.ch To: bounce.me@credit-suisse.ch Subject: mail test bla bla . 250 Whew! Done! Was it as good for you as it was for me? quit 221 It's been real. Take off Eh!