Cloudflare SSL handshake error even though I don't use cloudflare and other issues

[Dvalin21]

Hey guys, I'm trying to figure some things out before I post it as an issue or bug.

So I switched from NPM to Zoraxy. (I had to completely reinstall my entire server, starting with Zoraxy)
Zoraxy is in its own LXC.

So as I start adding containers in a ubuntu 24.04 server build, I noticed some issues with some of the docker containers I'm using.

I have Mail Cow installed on a separate tower and its doing great, no issues.
Except when I try to use the smtp on two apps, invoiceninja and Zammand (helpdesk ticket).
When I tried to connect my email to the apps, they now say

Connection could not be established with host "mail.example.com:587": stream_socket_client(): Unable to connect to mail.example.com:587 (Connection refused)

Now, I can send AND receive emails and also I got it attached to other apps like Vaultwarden, Bluemail, etc and able to send notification emails with it.

However, these two apps I'm not sure why I get it. I'm even able to connect via commandline so I now that the ports are not blocked and so on.

I really like Zoraxy so far, I would like to stay with it but I need to be able to attach email to these apps. Any thoughts? I've also posted this at invoiceninja and waiting for a response. Thanks in advance.