Logwatch doesn't proper handle IPv6 addresses in Sendmail log, for example:
Jan 26 20:20:52 tux sendmail[17402]: r0QJKfPa017402: tux.example.net [IPv6:::1]: EXPN root [rejected]
Jan 26 20:20:58 tux sendmail[17402]: r0QJKfPa017402: tux.example.net [IPv6:::1]: VRFY root [rejected]
See also: https://bugzilla.redhat.com/show_bug.cgi?id=904772.
2013-01-27 05:58:30 PST in Logwatch