I have a number of Exim servers behind a NAT gateway (actually connected
with vpn's to a cloud vps - but I'm hoping this is not relevant to this
post). I would like the gateway to send incoming port 25 traffic to the
correct Exim server based on SNI in incoming TLS packets - as different
Exim instances serve different email domains. The setup would look like
this:
[Internet]
|
|
(smtp port 25)
|
v
|
[Cloud server]
|
v
|
----------------------------------------
| | |
| | |
[Exim server 1] [Exim server 2] [Exim server 3]
I would have preferred to do this at IP tables level - but apparently
not really possible. It seems the next option would be HAProxy. Has
anyone here used HAProxy or run a setup as above, or know if this is
actually doable? Any suggestions much appreciated.
