Hi all! Im using ispconfig from years and no problems at all. Now i buy a linode vps & setup a new ubuntu server with ispconfig on it. Everything is working as expected but now i realized linode blocks smtp services on ports 25, 465 and 587 and as i read on this forum from what till suggest, email server not working if port 25 is bloqued. so now, i have to workaroung on this... i have a windows server on aws i use for sql and small things, im planning to install exchange 2019 on it and use as email relay. can someone guide me on this? thanks
How would an external exchange server as a relay solve your blocked incoming ports? Unless you're planning on using a vpn between the two exchange won't be able to reach your mailserver as well.
another postfix as a relay would be easier.. to send the mail out from the ispconfig mailserver you would need to configure the relay server to listen on a different port to 25 (if unauthenticated) .. not sure how easy that is on exchange.. linode blocking outbound connections to port 25 i can understand.. but inbound as well? and 465 and 587? seems unusual. normally they just block port 25 out.. whatever you end up doing.. you should ask aws to configure a ptr record and remove mail limits on your aws instance first.. otherwise you'll be no better off.. aws block port 25 by default, and they won't unblock it unless you have good history with them, and can provide a convincing reason for it.. otherwise they'll push you to use SES instead...
If it's about outgoing ports then it's posible. Create a new receive connector in exchange on the decired port. An ip filter can be configured and several forms of authentication among other settings. After that set the proper relay host and port ( [<hostname>]:<port> ) in ISPConfig with user/pass if decired.