I have two BT email addresses. Why is it not possible to have both inboxes open at the same time in Windows? It's so annoying having to "switch account" every time I want to check my other inbox. Even if I do have two windows open, with one email inbox open in the first, if I try to sign on to my second address in the second window, the first open window automatically changes to the second window's sign on.
Why not use the proper tool for the job instead of the bodge of webmail. Just use a mail client such as the free Mozilla Thunderbird and you can have as many inboxes as you wish in one place.