Gwcheck error 83 in my mailbox

There are some previous articles related to it, but none with an answer that solved for me.

I have setup my mailbox for auto-archiving after 90 days. My mailbox has stopped archiving mails from sometime and everytime I start the groupwise it gives me the error dialog "Groupwise has encountered a problem with your mailbox..." After searching for that, found gwcheck and started using to analyze the archive folder. It reported that many mails cannot be archived due to error 83.

Can somebody tell me how I can resolve this? I cannot lose all my mails and there is no guarantee that even if I do that this time, it won't happen again.

Thanks in advance,
Sailesh