I've received the same error. I have tried deleting the email account and starting again but I keep getting the same error. The email account is setup correctly and I can send email from the webmail app, but the account refuses to receive mail.
I have tried deleting and setting up the same account 3 times but always the same problem. I have tried setting up a test account (firstname.lastname@example.org) and it sends and receives without any problem.
The problem appears to be if I place a period (.) in the email address, example; email@example.com the problem occurs. But if I create an email address without a period (.) example; firstname.lastname@example.org there isn't a problem.
But to get the system to work using the address that I need is causing me the usual hair loss.
I appears there must be a problem on the mail server, is there anyway I could fix it? I have sent a ticket to support.