Mail server - How to expose ports for internal network

[ChicagoGregg]

Hello,

I couldn't find this question posed anywhere in the forum here (which is a little surprising as I thought it would be somewhat a common query)...

Nor can I find any hints at: https://docs.cloudron.io/email/#inbound-ports

Is it possible to expose its ports (25,465,587) to the local network so that mail can be sent (relayed) through the mail server and let it handle it going outbound? Figuring that Cloudron has this capability, and I'd only have a few emails per day requiring this, it should be able to provide this.

A docker inspect shows no ports are exposed (obviously). I haven't dug into where this could be changed to expose it -- and whether Cloudron would just overwrite it or not when starting up the next time.

Thanks!

-gregg

[subven]

@ChicagoGregg from the docs:

Email can only be relayed (including same-domain emails) by authenticated users using SMTP/STARTTLS.

So no, you have to use SMTP in order to send out mails. Not having all services and ports exposed (besides the ones on this list) is kinda vital to the overall security of Cloudron.

[girish]

@ChicagoGregg said in Mail server - How to expose ports for internal network:

Is it possible to expose its ports (25,465,587) to the local network so that mail can be sent (relayed) through the mail server and let it handle it going outbound? Figuring that Cloudron has this capability, and I'd only have a few emails per day requiring this, it should be able to provide this.

If I understand correctly, you want to relay mail via another mail server. If so, just sent the relay using the External SMTP relay configuration.

I am not quite following the part about exposing port 25/476/587 though. These are already exposed on the server. You have to configure your router/firewall to port forward those ports to the Cloudron internal IP.

[ChicagoGregg]

@girish said in Mail server - How to expose ports for internal network:

@ChicagoGregg said in Mail server - How to expose ports for internal network:

Is it possible to expose its ports (25,465,587) to the local network so that mail can be sent (relayed) through the mail server and let it handle it going outbound? Figuring that Cloudron has this capability, and I'd only have a few emails per day requiring this, it should be able to provide this.

If I understand correctly, you want to relay mail via another mail server. If so, just sent the relay using the External SMTP relay configuration.

I am not quite following the part about exposing port 25/476/587 though. These are already exposed on the server. You have to configure your router/firewall to port forward those ports to the Cloudron internal IP.

Sorry for the tardy reply here. Thanks for both of your replies @subven and @girish .

Originally, I was simply wanting to do something like

Home Network (App sends email) -> Cloudron (on home network) accepts mail for relay from local home network 10.x.x.x -> sends to server through Internet connection (to my already-configured mail relay server, External w/ authentication)

I was looking for an unauthenticated relay on the home network.

Well, I suppose that Cloudron can't provide an unauthenticated relay point. So, I suppose the workaround is simply to configure a user and relay using authentication using a domain that is configured.

I'm fine going this route... And I get why it's for that reason with security.

Thanks for the help!

-gregg