Hello! I have installed ISPConfig 3.0.4 and Debian by following the tutorial "The Perfect Server – Debian Squeeze (Debian 6.0) With BIND & Dovecot [ISPConfig 3]" I have to tell that i completely love it. There haven't been any big problems with the installation, everything works fine. But there is one problem. As i have read, smtp auth is on by default, but the thing is - i can receive e-mails from outside sources, but when i send them from server's squirrelmail, i get this error back to my inbox: Code: This is the mail system at host srv.site.net. I'm sorry to have to inform you that your message could not be delivered to one or more recipients. It's attached below. For further assistance, please send mail to postmaster. If you do so, please include this problem report. You can delete your own text from the attached returned message. The mail system <[email protected]>: host b.mx.inbox.lv[18.104.22.168] said: 554 5.7.1 Service unavailable; Client host [xxx.xxx.xxx.xxx] blocked using lbl-zen.bl.cert.lv; http://www.spamhaus.org/query/bl?ip=xxx.xxx.xxx.xxx (in reply to RCPT TO command) As far as i undestood from the spamhaus.org link, my ip adress is in a spammers list, and im unfortunately unable to send the mails until ill enable smtp auth.(that's what the suggest in the link) But here's the dilemma, as i mentioned earlier, all the sources say that smtp auth is on by default. So what should i do now? How i fix this problem?