Currently we I have a mail server for example "mail.example.com".
This is a dedicated email server and we are looking to replace it.
We are considering outsourcing the email management through multiple possible services (gandi email for domains registered there, opensrs for others).
The idea being we don't have to manage the server and we leave that to suppliers who know better.
Problem is we have 100's of clients on this email server and we want to make the transition as simple as possible.
Problem 2 is we ideally want to maintain our "mail.example.com" branding as we sell this customers and there first point of contact would still be us.
Email isn't something we I am fully educated on, I know that "mail.example.com" handles everything (SMTP, imap, webmail, etc.).
At first I thought cnaming mail.example.com to the downstream provider would suffice, however initial investigation suggests this is against the spec, and would cause certificate issues.
What I would like to do (don't know if its possible) is create a "proxy" that "mail.example.com" points to, and this proxy should decide by domain where to send the email (both sending, and receiving).
The point here is:
- "mail.example.com" would be retained
- The proxy can decide via the domain where to proxy the information to (i.e. gandi or opensrs)
I've come across NGINX mail module which appear to do what I want it to, but could use some guidance to ensure this is the correct route before delving deeper into what's involved.
I've seen the term "mail relay" is this just an email specific term for what I know as a "proxy"?
I'm also considering the impact of SSL communication for the proxy, we can secure the proxy itself no problem, but would this have an effect on the secure nature of the downstream services?
To be clear, I'm after clarification I'm on the right path, I'm aware there is probably much more involved which I can narrow down my questions with the knowledge I'm going in the right direction.
