Excellent question. WordPress relies on the server where it is installed to actually send out any emails. That can be transactional emails like receipts, new user registrations or comment notifications.
For every business, I suggest switching to a dedicated service for these types of emails. MailChimp has a good service for this called Mandrill that can send out your emails.
I’m a Google apps customer already so for several years, I’ve just used Gmail to send all my messages. There’s an article at WP Beginner (http://www.wpbeginner.com/plugins/how-to-send-email-in-wordpress-using-the-gmail-smtp-server/) that can show you how to set that up with Gmail or just about any SMTP email service you’re using.
One reason I like this option is all of my transactional email ends up in my sent mail folder. Otherwise I never have a copy of the email that gets sent out.
One last thing I’ll mention is a service called Receiptful (https://receiptful.com). It sends out receipts from WooCommerce for you. They look great and you can add in items like coupons to customers and more to the receipts.
Hope that helps out,
Bill