I think I've finally got it sorted. The oekaki is calling the PHP mail() function, rather than directly calling sendmail. PHP however, is trying to call sendmail with USER=root, so it's trying to find the .esmtprc file in /root/ instead of /home/millennium/ It used to work correctly, but now it doesn't. Bizarre. I've written a wrapper script that I HOPE will fix the problem. In my own testing it seems to, as I can now use a php script to send an email to my gmail account, as well as local xepher.net addresses. Try it on the oekaki, and see if mail goes through now.
My apologies, in that I didn't realize this had broken recently. Several other people used that with their php scripts to send mail, and it was working, so I just assumed it was more likely an issue with how you'd configured things, not realizing that they'd stopped using it in the mail() method. So in conclusion... My bad! :-P