Emails of customers who bought product X

Hi there,

I’d be SO grateful if you can help me with this! It will save hours and hours.

I want to email all my customers who purchased a particular book from my bookstore, to let them know that book 2 is out now. How can I do this without going into each previous order (of book 1) and emailing them individually? Some customers are registered but most are not.

Thanks in advance ??