I would invoke virtue #2, laziness and ask why your data structure can't look like this:

my %email = {
  Category1 => { "Name One",  'some1@address.com },
  Category2 => { "Name Two",  'some2@address.com',
                 "Name Three", 'some3@address.com },
  "Name One" => 'some1@address.com'
}
[download]

You see, the hash does not have to homogenous. When you do a lookup, either key the Category names so they're easily distinguishable (all caps, put a * in front) as a string or check to see whether the value of your hash key is a reference. If it is, dereference and lookup again. Or better yet, realize that what you really want is a hash of arrays, where when you provide a name you want one or more email addresses back. Note that you never return "Name One", only 'some1@address'. Try organizing like this:

my %Email = {
  'Category1' => [ q(some1@address.com) ],
  'Category2' => [ q(some2@address.com some3@address.com) ],
  'Name One'  => [ q(some1@address.com) ]
};
[download]