E-mail sending from PL/SQL fails with SMTP error 550 must check for new....

Question

We have a issue like this. We have a e-mail program (PL/SQL stored procedure which is called from a 10g R2 form) which sends e-mails using UTL_SMTP. It was working but suddenly from day-before-yesterday stopped working. Mail admin says he did not change any mail server paras.
The DB is in Linux so is the mail server. We finally did a code change. Now the mail goes to SMTP server but the mail does not go out of it (to a gmail address). We did a trace of the SMTP log and found out that it throws *550 [email protected] must check for new mail first* .
Here is the SMTP server log:
[192.168.0.6:25]
Wed 2012-04-25 18:52:46: --> 220 suninsurance.com.fj ESMTP MDaemon 12.5.4; Wed, 25 Apr 2012 18:52:46 +1200
Wed 2012-04-25 18:52:46: <-- HELO 192.168.0.6
Wed 2012-04-25 18:52:46: --> 250 suninsurance.com.fj Hello 192.168.0.6, pleased to meet you
Wed 2012-04-25 18:52:46: <-- MAIL FROM:[email protected]
Wed 2012-04-25 18:52:46: --> 250 <[email protected]>, Sender ok
Wed 2012-04-25 18:52:46: <-- RCPT TO:[email protected]
Wed 2012-04-25 18:52:46: --> 550 [email protected] must check for new mail first
Wed 2012-04-25 19:02:45: Connection timed out!
Wed 2012-04-25 19:02:45: SMTP session terminated (Bytes in/out: 96/256)
Wed 2012-04-25 19:02:46: ----------
Wed 2012-04-25 19:20:11: Session 17159; child 1What could be the problem here? Any help would be greatly appreciated.

Answer 1

Finally figured out the problem and fixed it. Now it is working.
*"must check for new mail first"* means that before sending mail you have to check your mails (i.e. download) your mails first from the mail server, because the normal setting is for SMTP servers is that you can send mail only if you received a mail. So, when you receive a mail (i.e. check mail), your IP is recorded in the SMTP server log. Now if you send a mail, only mails with the IPs which has received any mail will be allowed to send mails outside.
In order to only a send a mail without receiving any mail first you have to use SMTP authentication.
I.e. After
c := utl_smtp.open_connection(p_smtp_host, p_smtp_port);      
utl_smtp.EHLO(c, p_smtp_host);  You have to give UID/PWD for the SMTP server like this:
utl_smtp.command( c, 'AUTH LOGIN');
utl_smtp.command( c, utl_raw.cast_to_varchar2( utl_encode.base64_encode( utl_raw.cast_to_raw( p_un))) );
utl_smtp.command( c, utl_raw.cast_to_varchar2( utl_encode.base64_encode( utl_raw.cast_to_raw( p_pwd))) );However, when we sent like this we got a another SMTP error:
554 Message is not RFC compliant; missing "Date" header To solve this do this: Go to Setup -> Default Domain & Servers, Servers, uncheck ...refuse
messages which are not RFC compliant. That will allow MDaemon to accept  the malformed messages without date headers..Doing this solved the problem. Now we can send mails to outside mail boxes (like Gmail). In Gmail, when we checked the inbox there was no mail. It had gone the Spam folder. This is also important since you have to check the spam folder since Gmail will think it is spam. Once the mail is flagged as "not spam" it will start coming to your inbox.