ChristieAnn, 

Thank you for your prompt reply and advice on troubleshooting the issues. Much appreciated! 

I have managed to get around the mileage issue by entering them in as 2nd of July 2020 instead of the 1st, good enough for me. 

Invoicing emails still doing the same thing in the subject line.  

Invoice[InvoiceNo.]from

When clicking 'save and send' the above shows in the preview screen, in subject, before clicking 'send and close'. I've made a dummy invoice and confirmed that it still shows in the subject once sent to an email.

Thanks again for the reply, community section has been a big help. I originally followed procedure and used live chat help and also phoned through to the help desk which I thought would be the best way.