Hi,
Presently i'm working on FC1 and trying to configure Sendmail. I'm getting the error message like this "The message could not be sent because one of the recipients was rejected by the server" Relaying denied. IP name lookup failed Client machine IP', Port: 25, Secure(SSL): No, Server Error: 550, Error Number: 0x800CCC79. I'm trying to configure Outlook Express as mail client. Can any one help me in this problem

This problem happens because your version of Outlook Express is set up to use Secure Socket Layer (SSL),
To fix this problem:
* Open Outlook Express, and click Tools
* Then click on Accounts
* Then click on your connection and click Properties
* Then click Advanced
* On this screen remove the checks from the boxes This server requires a secure connection for both Outgoing mail (SMTP) and Incoming mail (POP3).

You will then be able to collect your mail.

Thanks for reply.

I lready unchecked the options ok SSL for SMTP and POP3. I'm getting the same problem. I'm using my ISP's DNS IP.

The cause of this error is due to the fact that SMTP server require authentication,this is a client side error i think...not a server issue

not sure if this is causing your problem, but by default sendmail is configured with mail relaying disabled (to prevent spammers using you as a free delivery service). go to your /etc/mail/access file and see what's in there. to allow people on your local network to relay, add a line like this:

192.168.1 RELAY

and if you want to add a computer you use at work or something, add another line like this:

10.71.110.50 RELAY

(but obviously put in a real ip address) then you have to save and close the file. while you're still in /etc/mail type "make" and hit enter. then restart sendmail and you should be good to go.

1 members found this post helpful.

What's in your /etc/resolv.conf file?
I was getting same error until I set up DNS servers in this file.

I already entered DNS Address in /etc/resolvconf