This question is a side-result of following Falko's excellent "The Perfect Setup" Debian Etch tutorial. With SMTPAuth turned on, I'm having an issue when I try to autoforward mail to the ISP inbox of my hosting client's local mail provider. Here's the scenario... I have Postfix installed on my etch 4.0r3 server together with the dovecot (IMAP and pop3) server, SMTPAuth, and TLS together with squirrelmail as my web mail client and SpamAssassin as my spam filter. I basically followed Falko's tutorial when setting up the server (with a couple of exceptions). This stuff all works fine and none of those apps per se seems to have any direct bearing on my current issue. Here's the problem I'm having... When I send an email to an inbox on the server, it arrives just fine. It can be downloaded and read with a mail client or accessed and read online using squirrelmail. However, if I set that same inbox up to autoforward all mail it receives to another location on the net using the sendmail/postfix “.forward” file (i.e. the final target email address is not actually ON my server but is the user’s private email inbox at their own ISP), I get the message I sent bounced back to me with the following error: firstname.lastname@example.org SMTP error from remote mail server after RCPT TO:: host mail.hissite.com [220.127.116.11]: 554 5.7.1 : Relay access denied This is a very common mail scenario for many of my hosting clients. They use an email inbox address on the server where their site is located with their site name attached but then they want the incoming emails forwarded to their inbox at their local ISP. It's a simple and perfectly legitimate mail forwarding request that I've used successfully for years. It appears SMTPAuth is blocking this because it sees it as a mail relay; but that’s exactly how it’s supposed to work and it's configured on my own server for gosh sakes. There are no nefarious tricks here. This is NOT some insidious spamming or anonymous email trick. It's just forwarding the emails from one or more sites to a single client inbox. Surely there must be some easy way around this "relay access denied" problem. This seems to me like a situation where SMTP has gotten a bit overzealous. Can someone please tell me how to work around this problem? Thanks!