Up until today I'd been using an outdated version of Webmail Notifier, which had a feature where if I clicked on the Webmail Notifier button in my status bar, it would load my inbox. It would also do the same when I right-clicked on the button and chose my email account from the dropdown box, or when I clicked on the link in the popup box that notified me when new messages come in.
X-notifier 3.2 does the same
X-notifier 3.2 does the same thing.
If it does not work, uninstall/reinstall X-notifier.
XN 3.3
When X-Notifier shows new email (orange icon), clicking the X-Notifier icon should open all the accounts with new email in their own tabs. When X-Notifier icon is gray ( no new emails), clicking the X-Notifier icon should open the account which is listed first in the X-Notifier Options defined accounts list. You can click an account in the list and move it to the top, with the arrow buttons to the right of the list.