My client has only just changed her mail server settings from the old Business Catalyst settings [mail.worldsecureemail.com] to [mail.b.hostedemail.com] in Outlook on her laptop.
But is still getting this warning popping up (screen shot attached)
My best guess is that they didn’t change it somewhere since it still mentions “worldsecureemail” in the alert window. I often experience problems with clients Outlook. If the error is persistent I would delete the account on the machine and set it up again. Sometimes it seems like it is “cached” - have experienced this on iPhones as well. When changing servers it will not work, delete the account, set it up again with the exact same details and it works