Windows Mail and MS Outlook do not share the same set of
accounts data.  Each keeps its own set.  They can, however,
download the same messages if you've set them both to save a
copy of downloaded messages on the server.

We're likely to need more details to help much.  For example, if
Windows Mail gives you error messages when you try to send
and receive, right click on them and copy the entire error messages
into your next message, even if they're not in English.