I've posted elsewhere and put in a ticket so they have it on file, but I've followed all of the steps and on my browser of choice I cannot access sitemail via mobile or my computer. If In fact, trying to do so locks up the webpage entirely and I have to close the entire window and reopen as even the back button or trying to type into the address bar does nothing. The cache-clearing link works on other browsers, but means I essentially have to login to two separate browsers to access WIS. My primary browser that I do everything (work and personal) in and use the forums and manage my teams, and a separate browser just for sitemail.
For the record, my primary browser on both computer and phone is Brave. I also use Firefox, Safari, Chrome, Opera, and MicroBrowser for different functions.
This only started happening with the sitemail fix they implemented.