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

Tip of the week: When trying to send email using UTL_SMTP in RedHat Linux Server getting following error

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

The "ORA-29278: SMTP transient error: 421 Service not available" error indicates that the problem is due to database server's network configuration not allowing it to contact an external server.

Solution:

We found sendmail to use a smart host was not setup caused the error. Below steps should give you the needed  details to setup and as well as check the configuration.

In your /etc/mail/sendmail.mc file there should be a line as follows:

dnl define(`SMART_HOST',`smtp.your.provider')

Remove the "dnl" section and replace "smtp.your.provider" with the fully qualified domain name of the smart host you wish to use so that the line reads:

dnl define(`SMART_HOST',`smtp.your.provider')

Generate a new sendmail.cf file by running

# cd /etc/mail

# m4 sendmail.mc > sendmail.cf

This will generate the .cf upon restarting the sendmail by

# service sendmail restart

However you can manually do this with the following command: make -C /etc/mail

If you still experience the error, perform the following diagnostics steps.

1. The first step is to send a message from the server you made the changes on.

[root@rhbox mail]# echo test1|mail -s test1 sunthar@oracletechnologistblog.com

2. The next step can be done on the server.

Once the message is sent you will want to tail or grep /var/log/maillog for the relevant email that was just sent.

Nov 11 09:51:14 aloha sendmail[31900]: pABEpEiF031898: to=<sunthar@oracletechnologistblog.com>, ctladdr=<root@dsunthar@oracletechnologistblog.com> (0/0), delay=00:00:00, xdelay=00:00:00, mailer=relay, pri=120370, relay=smtp.host.com. [10.180.1.103], dsn=4.0.0, stat=Deferred: Connection refused by smtp.host.com.

3. From the error message, its imperative that you need to open up the firewall to allow smtp.

Once thats resolved, you should be good to go.

Useful MOS note.

ORA-29278: SMTP transient error: 421 Service not available" When Using UTL_SMTP to Send Email [ID 604763.1]