To get store email id to phtml file
create a php tag to input the email field to the project.
For creating a php tag must be imported and it must contain the following code to retrieve the store email address.
$objectManager = \Magento\Framework\App\ObjectManager::getInstance();
echo $conf = $objectManager->get('Magento\Framework\App\Config\ScopeConfigInterface')->getValue('trans_email/ident_general/email');
the output for the code will be the store email address.