I think when you're small it really depends on your application. If email isn't an important part and you aren't sending high volume, then I definitely agree it can be a huge time-sink and very tough to figure out.
But if you really want control of your email it's not that difficult to do if you follow best practices.
WRT Return Path - I'm pretty sure Twitter turned to them when they had trouble delivering mail. Part of what they do is email whitelisting, which I fundamentally disagree with. But if you read the paper on how they helped twitter out with best practices there is actually a lot of good stuff in there (things that you can do on your own if it's important or you're at that scale).
But if you really want control of your email it's not that difficult to do if you follow best practices.
WRT Return Path - I'm pretty sure Twitter turned to them when they had trouble delivering mail. Part of what they do is email whitelisting, which I fundamentally disagree with. But if you read the paper on how they helped twitter out with best practices there is actually a lot of good stuff in there (things that you can do on your own if it's important or you're at that scale).