Send multiple checkbox values through $_POST via mail PHP

I am attempting to send my checkbox values through my mail form but it comes back as "None" every time. Thanks in advance for the help!

My code

                    <div class="control-group form-group">
                    <div class="controls">
                    <label>Services Required:</label> <br />
                        <ul class="checkbox-grid">
                            <li><input type="checkbox" name="services[]" value="value1" /> Text 11</li>
                            <li><input type="checkbox" name="services[]" value="value2" /> Text 12</li>
                            <li><input type="checkbox" name="services[]" value="value3" /> Text 11</li>
                            <li><input type="checkbox" name="services[]" value="value4" /> Text 12</li>
                            <li><input type="checkbox" name="services[]" value="value5" /> Text 11</li>
                            <li><input type="checkbox" name="services[]" value="value6" /> Text 12</li>
                            <li><input type="checkbox" name="services[]" value="value7" /> Text 11</li>
                            <li><input type="checkbox" name="services[]" value="value8" /> Text 12</li>
                            <li><input type="checkbox" name="services[]" value="value9" /> Text 11</li>
                            <li><input type="checkbox" name="services[]" value="value10" /> Text 12</li>
                            <li><input type="checkbox" name="services[]" value="value11" /> Text 11</li>
                            <li><input type="checkbox" name="services[]" value="value12" /> Text 12</li>
                        </ul> 
                     </div>

My PHP:

$selectedServices  = 'None';
if(isset($_POST['services']) && is_array($_POST['services']) && count($_POST['services']) > 0){
$selectedServices = implode(', ', $_POST['services']);}

$email_body = Services: $selectedServices

Any ideas?