Then how to make the service available? The envirment is Windows Xp +oracle10.2 ----- Original Message ----- From: David Sharples To: xiaoyezi.xyz@xxxxxxx Cc: oracle-l@xxxxxxxxxxxxx Sent: Thursday, July 27, 2006 5:33 PM Subject: Re: ORA-29278: SMTP transient error: 421 Service not available the first line tells it all, the smtp service isnt available at the server you are using On 27/07/06, xiaoyan <xiaoyezi.xyz@xxxxxxx> wrote: Hi,all When I try to use UTL_SMTP package to send mail,I got the following error: ORA-29278: SMTP transient error: 421 Service not available