SendGrid is an amazing company. I’m in awe at how much they have done in such a short period of time. We use them for our Freelancer Marketplace and are implementing some really interesting features (such as reply to the support email -> update your profile).
SendGrid sends email your app sends (friend requests as an example). Your app may send a million emails a day, and to take care of all the tech needs and compliance you will need a few employees. Or SendGrid. They have some great features like removing emails that mark you as spam in their email client from your lists or open rates for all emails.
If you run a site that sends transactional emails, it is a no brainier to use them. TechStars grad too!
They are gearing up for a fresh UI and design and hiring a few folks, I suppose.
Good news to nice guys, love hearing stories like this.