"This IP has been blocked" Contact PPRuNe administrator
This is very likely due to the amount of spam now emanating from China - IT ranges have been blocked by IB to prevent it.
The proportion of spam to legitimate access is by the far the worst in CHina - virtually all spam and virtually no legitimate access. 80-90% of the recent spambots were associated with Chinese IP addresses, for example.
Unfortunately it would appear that some collateral damage has occurred.
SD