hi iam using slackware 9 as a proxy to my 5 computer to access the internet and also iam using it as a mail server running sendmail.... it works fine in a week until suddenly my nightmare begin went i sent an email to my client and bounced back and the messages is:

----- The following addresses had permanent fatal errors -----
<new@abuse.net>
(reason: 553 Open Proxy - http://proxies.blackholes.easynet.nl/errors.html)

now i cannot send anymore to my client and even to my yahoo account....can you give me some advise on how to resolve this problem of mine???
another question? is open relay is the same as open proxy?
as far iam concern i just close my relaying outside my network.
i just edit etc/mail/relay-domains and deny external network and
only my private network can relay to my mail server.i tested it coz went i read my maillog it reject a spammer trying to relay a mail into my mailserver.

open relay and open proxy are 2 different things - have a look at the page that the url links to.

It may be that your ip address is being blacklisted because of your isps mailserver. Recently I discovered that Demon customers in the UK have been blacklisted because Demon's mail server is open.

Could be worth checking with your isp.

think ur right thks i will check that....