Dear Maintainer,

I commented out this section in /etc/hosts some time ago.
# The following lines are desirable for IPv6 capable hosts
#::1     localhost ip6-localhost ip6-loopback
#ff02::1 ip6-allnodes
#ff02::2 ip6-allrouters

Somewhere along the line exim4 added ::1 to it's lookup, which causes
"exim4 paniclog non-zero" issue, though mail still seems to work.

dpkg-reconfigure exim4-config and removing the ::1 fixes it.

Happy New Year, and thanks for the wheezy.