sky broadband error message

[stanwixman]

PERM_FAILURE: SMTP Error (state 13): 550 Unknown user
i keep getting the above error message when trying to get my sky email any ideas how to fix it and what does it mean?

[robotics]

look at www.skyuser.co.uk

helpful website for sky customers

[rojash]

The message would seem to indicate that you've entered your account name incorrectly