Assuming following system architecture:
internet | smtp.mydomain.com (TLS/SSL enabled SMTP-proxy?) | +--------DMZ----...----+ | | ... | iSMTP01 iSMTP02 iSMTPnn
The iSMTPxy servers are internal SMTP servers which shall not be publicly visible, but of course reachable internally in the DMZ.
What I am now searching is a possibility to "hide/proxy" all internal SMTP servers. Is there a standard way of doing it?
Alternatively what would be your suggestions, to handle tons of mailboxes if you cannot handle these amount of mailboxes on one SMTP server? But for the endusers the Mailserver should be always reachable via one DNS name?
If you take in consideration how the big Providers are doing, they do exactly this thing. E.g. one of germans biggest provider has one central SMTP DNS address smtp..com
And from the load it would be unbelievable that they are not using a load balancing and a distribution of the SMTPs over multiple hardware nodes.
In my case, the internal servers are postfix(es)
How would the SMTP-proxy be solved in a standard way?