Thank you for the reply. Seems a dead end then with the ISP I use.
I have my own hosted Centos server which I use for DNS and mqtt, I could set up a dedicated mail server specifically for this that will talk SSL/TLD on port 465
What would you suggest as the best route to go on Centos? Old tried and tested Postfix?
I did try the gmail option, I could not get it to work, but not really keen on being dependent on google services.
thanks again,
Bruce