Add a !!todaysdate!! variable for use in Paid Memberships Pro email templates. Add this to your active theme's functions.php or a custom plugin and then include !!todaysdate!! in your email templates.

my_pmpro_email_data.php

/*
	Adds !!todaysdate!! as an available variable for use in Paid Memberships Pro emails.
	
	Notice the array key does not include the !!s
*/
function my_pmpro_email_data($data, $email)
{
	$data['todaysdate'] = date(get_option("date_format"));

	return $data;
}
add_filter("pmpro_email_data", "my_pmpro_email_data", 10, 2);