I've been going around and around in frustrating circles for 2 days now, trying everything recommended with nothing working.
FINALLY I have success, email sends and receives.
What I did -
On setting up email account on the new laptop, TURN the internet OFF on your old laptop.
AND make sure the apps are turned on for 'contacts' & 'calendar'. Like magic it now works, I think the apps were stopping the connection from sending/receiving.
If I can do it, you all can too.
Now, how to figure out how to import my contacts when there's no such icon in windows 10 mail!
Good luck 