This article on SendGrid is helpful. You do need to set up a separate MX record on a subdomain (or other domain) for inbound "parse" replies.
Email for Amazon SES?
I'm switching from Mandrill to Amazon SES. There is an option to send using SMTP.
I wasn't able to find an up-to-date version of the Amazon SES plugin that works with NodeBB >= 1.
Similarly, based on the Git issues, it looks like the emailer-local and emailer-ssl-smtp plugins also aren't compatible?
What are you guys using for SMTP?