Mail Server - Unable to specify

[ServerCaseUK]

Hi All,

New to 3CX - Been getting used to it for the past couple of weeks and loving it.

One of the issues I am having though is the Mail Server setting. It only lists "3CX SMTP Server" in the dropdown. There is no option to change it and it won't allow me to specify anything else.

When I click on the Test button, I get the following error;

Unable to read data from the transport connection: An existing connection was forcibly closed by the remote host.

I'd ideally like to change this anyway to our ISP's SMTP relay.

Any ideas please?



Thanks.

 

[Saqqara]

If you are using standard license, you can only use 3CX smtp servers.

3CX smtp servers use port 2528 , make sure if is open on your firewall.

 

[ServerCaseUK]

It's definitely open on our sonicwall firewall for outbound access. System has Windows firewall, but I don't think that should be restricting any outbound? Do you know the FQDN/IP of the 3CX SMTP so I can so some traces to see how far it's getting? Thanks.

 

[Saqqara]

Does 3CX FQDN match your external IP address.

 

[ServerCaseUK]

It does yes. 3CX itself is working great - Firewall test passes all green. Only issue is with the Mail Server setting so far.

 

[cobaltit]

Regarding using your ISP relay, you'd need to upgrade to PRO or higher to specific a SMTP server other than 3CX. I'd try restarting your instance and make sure there's no AV on the machine.

 

[ServerCaseUK]

Already tried a restart but didn't help. We do have AV on the machine as it's on our network so we must use Sophos EndPoint security - No chance I am having a Windows machine without anti-virus I dont think Sophos should be interfering though. I think I may just have to live with it for the moment.

Is there a comparison of the difference between Standard and Pro?

 

[Saqqara]

I would temporary disable Sophos Endpoint, as I have seen this block port numbers. As 3CX uses 2528, I would guess this software is blocking it. If it works, you need to open this port up.

Comparison list https://www.3cx.com/ordering/pricing/