Can't access email on one out of four addresses

I have 4 Hughesnet email addresses. 3 work perfectly, but 1 gives an error 500 across all devices. I can receive and send emails, but when going to myhughesnet to delete old emails, I get the error code.

Password has been reset, incognito window = same result. NUMEROUS calls to hughesnet resulted in nothing. This is for a business and is EXTREMELY frustrating!!!!!!  Please advise/help/fix!!!!

Can a moderator please escalate this to engineering to repair my mailbox profile?