Links like this are stupid regardless of Outlook's behaviour because they require a perfectly reliable client and network and user in a perfectly undisturbed flow. If I can't F5, if I double-click, if my mouse is wonky, my wifi is bad, my power goes out, my computer hangs, my DSL dies just after a click, if I accidentally close the tab.. there are any of a thousand reasons why abusing GET for a one-time-use page or redirect is horribly wrong.
It takes incredible arrogance to continue using them in order to "improve usability" given all the obvious and common cases where they completely destroy usability. The difficulty for a provider to verify they aren't sending you to a phishing or browser 0day page barely scratches the surface.