Can't connect external MQTT using domain name?

I can connect MQTT broker in local network, but can’t connect when I use domain name. who can help me

hello All .
please support me.

Similar problem for me (still investigating but no cue so far). Using the same MQTT client, I can connect when the client and OpenRemote are co-located (same machine) but it fails more or less silently when trying from another machine on the same local network, with exactly the same credentials. I suspect the problem is with the proxy but none of the components is very verbose in this respect.
Still searching but any hint would be appreciated (at least as to where to look in the logs for more info).
Best regards,

Sorry for the late reply,

When crossing machines or networks (LAN ↔ WAN) then you need to make sure the ports are exposed, sounds like this is the most likely issue.

Typically you want to use MQTTS (if using self signed certificate then you need to disable certificate verification in your MQTT client) and you would then make sure port 8883 is exposed to your LAN or WAN as required.

If you want to use MQTT (without TLS) you will need to map port 1883 from the manager container, this is discussed in another post.