Can I use my email during the import?
You can use both your source and destination accounts to send and receive email during the import. However, try limiting your usage to just the online webmail service. Accessing your email from external clients (such as Outlook, Live Mail, Thunderbird, etc.), tablets, and phones during the transfer can interrupt the process.
Additionally, if you receive email in the old account after the import is finished, those email messages will not be migrated to your Comcast account.