It’s possible that it might be a hurdle @wkeithg , as they often use things like that to verify/link to an account. 
Do you not have an option to send otherwise? 

Thanks.  I’ll check if I can tweak something in my email client.

Discovered that bizarrely my ipad sends from the email I use for chargeanytime so I have re-sent my mail from there.  Interestingly I cant set up my email client using that account - virgin media seem to have blocked setting up a new one but they are happy to let an existing one login!

You need to migrate away from ISP email services sooner or later - they’re all slowly going the way of the dodo.

You are right but as a 68 year old techie I (and my wife) have got about 30 years history of using this address as an identifier so it’s a big job to change.

They responded to my email from my different account so using an email that is different from your login doesn’t seem to be an issue.