Error when adding subscribers via API?

Hi all,
I am having some trouble adding subscribers to my list using the API

require 'httparty'
require 'json'

def request
    url = 'https://api.createsend.com/api/v3.1/subscribers/MYLISTID.json'
    auth = {:username => 'MYAPIKEY', :password => 'x'}
    response = HTTParty.post(url, 
:basic_auth => auth, :body => {
'EmailAddress' => 'mike@hotmail.com',
'Name' => 'Test',
'Resubscribe' => true,
'RestartSubscriptionBasedAutoresponders' => true
})
 puts response
 puts response.code
end
request

I can make other requests but when I run this code I get the error message

{"Code"=>1, "Message"=>"Invalid Email Address"}
400

I can assure you that my email is a valid email.

Any help would be much appreciated as I am completely lost at this stage. This post can also be found on Stack OverFlow here
Stackover Flow

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