if we setup Amazon SES as mail delivery channel this to be used for member emails as well?
There are long-term future plans to have bulk email adapters but nothing short term.
The integration with Mailgun is not going to be shallow - it will have full stats on deliverability, open rates, click rates, automatic unsubscribe of members that mark newsletters as spam, and so on. Once we have a good idea of how all of that is working then we can look at making a universal API that would allow different adapters to be used but right now we’re focusing our attention so that we can deliver and iterate on the feature quickly. Everything in members is still beta remember ;-)