Can't use string ("foo@bar.com") as a HASH ref while "strict refs" in use at ./test.pl line 14.

##</code><code>##

# Data Structure.
#$spam_hash = {
# 'email@address.com' =>
#               {
#                'Subject1' => {
#                                cache_name1 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               },
#                                cache_name2 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               }
#                              },
#                'Subject2' => {
#                                cache_name1 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               },
#                                cache_name2 => {
#                                                 path => 'path',
#                                                 from => 'from'
#                                               }
#               }
#};