Dear Group.

I had a problem with courier mail server. I need to authenticate the mails via esmtp,only the valid users must able to send mail via my mail server. So I made

AUTH_REQUIRED=1 in /etc/courier/esmtpd

But my problem is that, I could sucessfully use this mechanism from all mail clinets,thunderbird. So that I can send mail via my server,eg: example.com to gmail or yahoo. But when I type a reply to this mail from gmail or yahoo, it give me the error message

Connected to <"exmaple.com IP"> but sender was rejected. Remote host said: 535 Authentication required.

I know that to mail, I send to example.com by via my mail client and the mail I send as reaply from gmail.com is actually getting authenticated via the example.com. But I only need to authenticate the From field from the mail clinet, beacuse different people can send me mail to my example.com by there own mail account. My problem is how to tackle this situation. The others must be able to sent to me at example.com account, if my account is valid.

I Made

AUTH_REQUIRED=0

Then lots of spam mails had started to queued up in mail mail spooler. How do I make my system from spam realys. I need to get my accounts authenticated when a mail is sent from a mail client and others can send me mail if the to account is a valid one.

Please do help me. Thanks in advance.

Regards Shyam