Error sending email

Pat73 · May 9, 2024, 2:39pm

HI,
I’m using a GL-MT300N-V2 to connect my device to a VPN.
This device of mine needs to send emails, but the emails are blocked.
I tried to set both port 25 and 587, but unfortunately they don’t come out.
Could it be a DNS problem?
My device has the GL-MT300N-V2 IP as the main DNS and the classic 8.8.8.8 as the secondary.
The GL-MT300N-V2, because it is connected to the WAN port to my network, sees my 192.168.10.xx as DNS

I tried opening the doors and had no changes, does anyone have any suggestions?

Thank you

admon · May 9, 2024, 2:44pm

Mostly VPN providers don’t allow sending mails, so you should check without VPN first.

alzhao · May 10, 2024, 7:29am

Why does VPN block emails?

admon · May 10, 2024, 7:34am

Some VPNs (especially free versions) do not release all ports so that you can’t get up to any trouble. Port 25 in particular is often blocked.

Even without a VPN, this happens from time to time, for example with German home Internet connections.

But even if this isn’t the case here, it would be smart to check without VPN as well - to remove just one variable from the equation.

Pat73 · May 10, 2024, 9:42am

HI,
if the VPN is not active I confirm that the emails are sent correctly with all ports (port 25, 587 and 465).
The VPN I connect to is not public, but it is my VPN on pfSense firewall. Sending emails with other devices hooked directly to the VPN without the GL-MT300N-V2 sending emails correctly

admon · May 10, 2024, 9:54am

Do all other services work? Surfing? DNS probing?

Pat73 · May 10, 2024, 10:28am

I haven’t tried them, what can I do?

admon · May 10, 2024, 10:32am

Surf the web while connecting to your router and VPN.
Try surfing to websites you didn’t visit before.

Pat73 · May 10, 2024, 1:07pm

If I isolate my PC from the network and connect it via wifi directly to the GL-MT300N I see the Mango on 192.168.8.1 but I cannot browse the web

admon · May 10, 2024, 3:43pm

Time to check the DNS settings then.

Pat73 · May 13, 2024, 9:58am

HI,
It’s not a DNS problem and maybe I found the solution, but I would like to understand the difference between these two options

Immagine 2024-05-13 114847

In my application I don’t have to mask my IP via the VPN, but I have to have protected traffic for viewing the pages of my Webserver and I have to send emails

Can you tell me when to use one or the other option?

Thank you

alzhao · May 13, 2024, 10:08am

This is the vpn policy:

Auto Detect: Use the routing from vpn config files or use the pushed routing from vpn server.
Manual routing rules.

Not supposed to use this two for non-exprienced users.

Pat73 · May 13, 2024, 12:37pm

Enabling one of these items correctly exits emails from the router.
My VPN does not allow web traffic.
The VPN was created only for direct connection capabilities to my device connected to the LAN port

My question was precisely to understand which of the two options to use while maintaining the security of the router and the network where installed.

If I don’t resolve the issue I can’t use it and consequently I won’t buy any others

admon · May 13, 2024, 1:09pm

To answer this question more precisely, we need at least a network diagram.

Pat73 · May 13, 2024, 2:11pm

Sorry for the very simple scheme.
My system allows the user to connect via our cloud to a device he has at home from anywhere in the world.
The secure connection is guaranteed by multiple factors including the introduction of the VPN.
To signal its presence and communicate the router’s dynamic IP, our device needs to send e-mails.
We use Mango for VPN management (Client).
The user can connect to his device both inside and outside the home

alzhao · May 13, 2024, 2:23pm

But if you choose these two policy but didn’t configure anything else, your data does not go via vpn at all.

Pat73 · May 13, 2024, 2:33pm

Sure, I’ve outlined my network for you.
Obviously in Mango I have loaded the VPN configuration and Port forwarding as well as everything I need to reach it from the outside.
The problem to be solved is the email output which only works with the two settings and I would like to choose the best one

alzhao · May 14, 2024, 6:19am

I see. If you only want to reach the router from the vpn, then pls choose “Customized routing rules”.
VPN will just be a tunnel without routing your data before you set up anything.

Pat73 · May 14, 2024, 10:28am

thanks for the answer, but when I create the rule I obviously have to put the IP of my device (Webserver)… correct?
What if I have multiple devices on my LAN with Mango?

alzhao · May 15, 2024, 10:34am

Maybe you can try port forward?