I'm having this problem this morning. Never happened before, tried clearing the cache didn't seem to work.
@Maryloumiller do you have any saved bookmarks for Shaw webmail that you are using? It may be something cached in the web browser causing this.
Try to delete any saved bookmarks, then open http://webmail.shaw.ca directly in the address bar of the web browser and try to sign in again.
Other thing to test would to try in a different web browser version (Microsoft Edge/Firefox/etc).