I work as an engineer for an email service provider. I can tell you that deliverability is one of the core things you bring to the table when you are doing sen

I work as an engineer for an email service provider. I can tell you that deliverability is one of the core things you bring to the table when you are doing sending for a lot of people. It's the sloppy, people oriented aspect that developers ignore (imagine you've got a huge send going out and gmail just flagged you as a spammer, you better have a contact there to fix it fast). Sure, you can write an app to send a million emails in a few minutes, but your work (and bandwidth costs) are pointless if it never makes it to the customer's inbox. There are a lot of dirty details in sending at volume. But like the old saying goes, "where there's muck, there's brass."