I've done some searching but have not found an answer to this particular problem yet.
I have tried configuring my Unitronics PLC to send email, and have followed the instructions for initializing and connecting the socket connection to a gmx email host. However, I have noticed that when I telnet to the mail.gmx.com server through port 465 (the only port I can connect through), I get a connection for only about 20 seconds before it is 'closed by foreign host'. It seems like maybe the port is not correct? I have tried 25 (which does not let me connect) and 465 because I found those ports online.
I think the same thing is happening in the ladder code, because i briefly get a successful indication of connection, but then it gets reset.
Has anyone seen this issue before? I was under the impression that GMX was a validated email host to use with these PLCs, so am I doing something wrong?