Many companies are already solving the same problem, and then resend comes into the picture with the support of YC. They are doing everything except sending the mails.
They do, or do not operate MX and deliver SMTP traffic to other mail servers?
They are a wrapper over AWS SES
so, great, something that still serves the purpose of funneling more unsolicited marketing email (spam) into peoples' inboxes, just with a shiny wrapper on it.
Wait really?? So what is it you're actually getting for a presumably marked-up price?