> Can you not use [complex technical sultion] > No need to make more work for yourself.

Recommending somebody to 'just use' some complex technical solution is a very typical and dare I say naive HN response.

Properly running an email service is a hard technical task. The days of just installing sendmail and expecting your email to actually arrive are long gone. Properly running an outbound email service requires knowledge on many domains (networking, system administration, DNS, cryptography, etc. etc.). It also requires plenty of maintenance.

So unless you are actually building an email service, just use a third party like Mailgun and focus on the product that you actually want to build.