Unable to send emails from reckon accounts plus 2016

Hi,
I currently use Reckon accounts plus 2016 and windows 10, I have recently moved, since moving, every-time i try to send an invoice i get the message email address or password invalid.

I have checked both and they are correct in the system. (edit/preferences/send forms,I can log in to email through google or Microsoft mail no problems).

However when i spoke to my accountant about this and we tried sending invoices through their service provider,I was able to send them. Came home tried again, didn't work, and same message.

I have temporarily removed my internet security in case it was a firewall issue, same result unable to send.

Would greatly appreciate if anyone has any other suggestions as how to try and resolve this issue.

Regards,
John