I currently us a combo because some of our emails are reports that take a bit to compile. So, the async method makes sense there. But every one of our nodes h

I currently us a combo because some of our emails are reports that take a bit to compile. So, the async method makes sense there. But every one of our nodes has a local postfix config and transport up to SendGrid. I trust Postfix will do a better job dealing with temporary outages than I will in Ruby. I'd imagine this is great for those on PaaS where they can't just install local software like an MTA, too.