I am testing 5 users with Office 365. Rather than a complete switch to Exchange Online I have redirected emails from the current 1and1 mailboxes.
I have manually configured Outlook 2013 with the Office 365 settings and it has connected to the mailbox.
I am in the process of importing the old .pst files.
I am constantly getting a pop up message asking me if I want to allow a website to automatically configure the account. The URL is for 1and1. I have cancelled the warning but it continually keeps popping up.