Comcast to yahoo conversion time needed to convert

When you click to accept the yahoo terms of service….

1 - how long does it take to complete the process and have all your emails and folders moved and accessible to you?

2 - is the process automated so that you can do it 24 hours a day with no delay if you do it during non business hours?

3 - what happens to any emails sent to your account between the time you accept the terms of service and the process is completed?