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.
I'd imagine this is great for those on PaaS where they can't just install local software like an MTA, too.