I have a different box running exim+courier, and decided on my Gentoo box to try using Courier only.

Somewhat painful, but ok. The gentoo install needed a fair amount of tweaking and creation of extra directories, etc to work right, but now I'm (almost) victorious...

...except for smarthosting. This is a family server (ok, basically it's just for me), so I want local mail delivered locally and everything else sent through my ISP's mail server. Good so far (it really is; I love the webadmin/webmail interfaces, etc).

But the smarthosting doesn't work, because Courier is correctly setting my server ID; here's what my ISP's relay says:

---------------------------------------------------------------------------

UNDELIVERABLE MAIL

Your message to the following recipients cannot be delivered:

<target@ip_address>: mail.myisp.net [68.168.78.100]: >>> MAIL FROM:<me@myserver> BODY=7BIT SIZE=641 <<< 553 myserver.isp.net does not exist

(where "target@ip_address" is the To: address, "mail.myisp.net" is my ISP's mailserver, and "myserver.isp.net" is my ISP's best guess at what my machine might be, which of course doesn't exist in DNS).

Now...

...when I was using sendmail, I think I remember a "masquerade_as" ability. In the Exim configuration files that I'm using, I don't see anything at all that looks like a masquerade, yet it's working.

Now, I was able to send an email from the command line (well, from mutt) to an outside address by setting the MAILHOST environment variable to a real mail host (my external mail host, not part of the isp).

But I'd rather have this set in courier proper, so that I don't need to configure all my external mail programs. And yet I'd still like to maintain the convention that emailing "user" will go to user@myserver while "user@ip_address" will go through the smarthost.

What's the combination of configuration variables necessary here?

-->VPutz