Here are my Thunderbird settings that worked through 4G broadband,
so it should work on all (I hope)
server name:- mail.optusnet.com.au
connection security:- STARTTLS
Authentication method:- No authentication
I hope this helps everyone as Optus has gone AWOL on this subject
That is bad, very bad.
Does Optus treat its customers like crap? YES
Do Optus go AWOL in threads? YES
Do Optus now resemble Helstra? YES
Well, they are the YES mob
The consensus seems to be SMTP you need to use port 25 - and it can be either insecure (which I wouldn't recommend), or using TLS for security. Port 465/587 don't seem to respond at all.
Now whether your mail client supports this setup is another matter altogether - I send most of my mail through Gmail's web client and it works OK.