I seemingly have everything installed and setup correctly. The API connects, I can see my lists & forms in the feed setup. There doesn't appear to be any issues in the setup.
If I complete the form, everything seems to work properly with the one major exception that the email address is not added to the mailing list. It's not anywhere in madmimi, even in the suppressed list. I tried clearing the plugin and starting over, but I had the same result the second time around. The form is at wallgalleries.com/contact. I don't really even know where to start on troubleshooting this.