How can I keep emails received from certain email addresses out of my “promotions” tab in Gmail?

I’m OK with GMail’s promotions tab keeping away most of the corporate newsletters I receive out of sight whenever I want to read my email.

Sometimes, however, GMail thinks an order confirmation qualifies as a promotion. I don’t want that. And for some companies, I do actually want to receive every single promotional email among my ordinary mail, so I’m less likely to miss out on it.

I read somewhere that adding an email address to the address book should prevent this, but this definitely doesn’t always work. For example, if an email is sent through MailChimp, GMail doesn’t seem to care if an email address in your address book and it will put an email under the promotions tab even if its from address is an address in my address book.

Is there a better way to configure GMail, so emails from a certain email address (or a certain domain) never are labeled as promotions, regardless of whether they’re sent through a bulk mailing vendor like MailChimp?