Keats,
No luck, the product just won't do what I want. It's so simply done in Exchange, but o365 makes it pain. I guess we might as well close the thread. Doesn't appear there's going to be a way for me to make this work given the product's limitation.
In the web version of Outlook that is possible. In the Windows based Outlook, there is no option to choose my connected account to send as. Also, that is an additional step I shouldn't have to do. This is what I mean by having a seamless integration. The way I have it configured on premise when I hit reply it's always as my earthlink.net address.
