Despite the fact that I've followed the instruction of the Swisscom internet page, I cannot complete the workaround because on step 4 of 7 the procedure stacks. I click on End but the system shows once more the End button.
I cannot use the Repair procedure since I don't have any Bluewin Account configured in Mail. The Install procedure isn't completed on Step 4/7, I click on Done but the system doesn't do anything (only a swift refresh and the Done button reappears). The only chance to proceed is to click on Cancel.