Retrieve default value of email field

$field->display:

$field->default_value;

[id] => 49 [field_type] => email [name] => e_mail [label] => E-mail [description] => [isfilter] => 0 [iscore] => 0 [issearch] => 1 [isadvsearch] => 0 [untranslatable] => 0 [formhidden] => 0 [positions] => [published] => 1 [attribs] => display_label=1 size=30 required=0 allow_multiple=0 max_values=0 default_value=webmarketing@quintadolago.com use_title=1 default_value_title=Contact us by Email! title_usage=0 pretext= posttext= separatorf=1 opentag= closetag= [checked_out] => 0 [checked_out_time] => 0000-00-00 00:00:00 [access] => 0 [ordering] => 47 [item_id] => 887 [value] => Array ( [0] => a:2:{s:4:"addr";s:29:"webmarketing@quintadolago.com";s:4:"text";s:20:"Contact us by Email!";} ) [parameters] => JParameter Object ( [_raw] => display_label=1 size=30 required=0 allow_multiple=0 max_values=0 default_value=webmarketing@quintadolago.com use_title=1 default_value_title=Contact us by Email! title_usage=0 pretext= posttext= separatorf=1 opentag= closetag= [_xml] => [_elements] => Array ( ) [_elementPath] => Array ( [0] => /var/www/quintadolago/libraries/joomla/html/parameter/element ) [_defaultNameSpace] => _default [_registry] => Array ( [_default] => Array ( [data] => stdClass Object ( [display_label] => 1 [size] => 30 [required] => 0 [allow_multiple] => 0 [max_values] => 0 [default_value] => webmarketing@quintadolago.com [use_title] => 1 [default_value_title] => Contact us by Email! [title_usage] => 0 [pretext] => [posttext] => [separatorf] => 1 [opentag] => [closetag] => ) ) ) [_errors] => Array ( ) ) [display] => Contact us by Email! )

$default_value= $field->parameters->get( 'default_value', '');

$field->parameters = new JParameter ($field->attribs);