On 14 May 2023 02:36, Tom Reed wrote:
$ telnet 193.106.250.xx 587 Trying 193.106.250.xx... telnet: Unable to connect to remote host: Connection timed out
Run wireshark/dumpcap or tcpdump on the client to check if you get the TCP reset packet.
You can also run it server-side, to see if the server ever sends it.