How can I use email notification for other notifications ?

Hello

Can i use email method in litecart for notify product sold out by sending email to seller ?

Yes

https://github.com/litecart/litecart/blob/bb865074b724dfc747ba2cd6f271950e52c0a4cc/public_html/includes/entities/ent_order.inc.php#L811-L816

is it possible to send email in localhost without any configurations of Litecart ? I mean by email function of litecart