Hi all, I hope someone can help me with this. I run postfix and everything has been ok. Now i see the following in my logs

reject: RCPT from localhost[127.0.0.1]: 554 <ephemera@kcnet.net>: Relay access denied; from=<SharonColumbo@hotmail.com> to=<ephemera@kcnet.net> proto=ESMTP helo=<hotmail.com>


and

to=<***.*****@capitaltrustnigeria.com>, relay=mx1.biz.mail.yahoo.com[67.28.113.136], delay=1831, status=deferred (host mx1.biz.mail.yahoo.com[67.28.113.136] refused to talk to me: 451 VS1-IP Excessive unknown recipients - possible Open Relay http://help.yahoo.com/help/us/mail/spam/spam-18.html (#4.1.8) 80.248.14.14)

Can someone tell me what it means. I hope someone is not trying to relay through me.

Also i have a lot of mails in my queue and some of them are not valid domains. Postfix keeps trying to send this mails. How can i delete mails in the queue?
Thanks

Hello,
While newbie but interested in postfix configuration myself, I looked for some answers to your questions and found this tool, maybe you could check the security of your server here first ?

Thanks,
i tried it and got this error
Default domain is staff.iinet.net.au

Connecting to ***.***.***.***...

FAILURE

Unfortunately the program failed because...

Open socket failed.
I have no idea what it means can you explain?

Your server is probably unreachable from the outside; are you behind a NAT or a FW ?
Is it supposed to accept connections from outside your local network ?
If not, you can't be an open relay.

the output of postconf -n would go a long way in determing what might be wrong with your configuration..

Also verify mydestination, mydomain, myhostname, mynetworks are all set correctly in your postfix configuraton. if these are incorrect you can cause the server to allow relaying or cause other servers to deny mail from you.

also make sure the hostname on your mailserver is set to the FQDN that is registerd to be your mail server, and set in the myhostname variable, and that rDNS has been configured for your mail server by your DNS hosting provider.

If a mailserver you are attempting to send mail to does a rDNS lookup on your mail server and doesn't get a valid response it may deny accepting mail from you.


If a mailserver you are attempting to send mail to does a hostname check against the name your server provide during HELO and doesn't get a response that matches the Registered name of your server it may deny accepting mail from you. as well as submit your server to a blacklist.

Setting your Hostname
http://www.cpqlinux.com/hostname.html

rDNS
http://en.wikipedia.org/wiki/Reverse_DNS_lookup

As for the Queue, the mail in the queue will time out eventually and be removed by postfix automatically, this is set at 5 days by default. This 5 Day time limit is INTENTIONAL, and is part of the design of a proper mail server so you probably don't want to change it.. maximal_queue_lifetime (default: 5d)