On Sun, May 14, 2023 at 08:36:38AM +0800, Tom Reed wrote: > tcp 0 0 0.0.0.0:587 0.0.0.0:* LISTEN > 32157/master > > > And the telnet results: > > $ telnet 193.106.250.xx 587 > Trying 193.106.250.xx... > telnet: Unable to connect to remote host: Connection timed out
So, it looks like it's not a LAN address. It's a mail server on the public Internet? As in, your telnet client and your server are NOT talking directly to each other over a straight ethernet connection? There's routers and stuff in between them? You'd need to investigate the possibility of a firewall-equivalent at each hop along the way.