Email not working at all - says no messages found in this mail box

I have multiple emails attached to my domain name. The main one (of course) has ceased to work today coming up with a blank page and no mail folders or anything saying "NO messages found in this mailbox". The other email is (at this stage) working fine. Given I am in Australia the time difference is making it a challenge to contact anyone at Homestead. Does anyone have a direct email support email?? Or know what is going on?? I have checked via a domain lookup and nothing appears to be suspended. Website is still working well. Thanks in advance! Anna