Configuring nullmailer on Linux?

Question

I'm setting up a new Linux Mint 12.0 installation, and oddly enough, it doesn't come configured with any sort of local mail.

What it has, instead, is nullmailer — a daemon that does nothing but forward mail to remote machines. The idea is that when something like crond sends an email, nullmailer will forward it to a remote smtp server, instead of to a local mail spool.

Which is fine: configuring local mail has always been a hassle. I generally configure my local accounts to forward to the mail accounts I'll actually be reading, anyway.

But that leaves me with the problem of configuring nullmailer. The OS installer left it in a configuration that didn't work. I needed to edit /etc/nullmailer/remotes to specify smtp and username and password. With that set, mail to remote addresses didn't error out, as it was handed to my chosen smtp server.

Next step was messing about with /etc/mailname, /etc/nullmailer/adminaddr, /etc/nullmailer/me, etc., until mail to root, root@localhost, myuser, myuser@localhost, etc., didn't fail with unknown domain errors, etc.

So now, I'm not getting errors handing mail off to my ISP's SMTP server. But I'm not seeing the mail in the destination account, either.

Is there a way to set the debug level, in nullmailer, so that I can see what it's using as to address, from address, reply-to address, etc.?