Inaccessible emails

[Puthick Hok]

Hi,

I'm using cyrus-imapd 2.3.7 with postfix and thunderbird as the client. 
My boss mailbox is about 17GB with around 56000 emails directly in the 
inbox. Now he has a problem opening his email from thunderbird 10. When 
he double clicks on some messages, thunderbird opens a new tab but the 
message content is blank. Sometimes by clicking forward or reply, 
thunderbird displays the message content as the quote message. This 
problem is not happening on every email message. This is rather erratic. 
It's not always the new email message.

I have reconstructed his mailbox from cyradm and reduced the period when 
squatter runs from 2 hours to 1 hour. All of these do not help or fix 
the problem.

To be honest, I don't know for sure the problem is. I can only guess 
that the size of his mailbox and the number of messages left directly in 
the inbox may be the problem. However, the same message that cannot be 
opened by thunderbird is accessible from squirrel mail. So, at least I 
want to know what to explain to him the problem.

It would be much appreciated if anyone could explain this problem to me 
and/or suggest a solution to this problem.

Thank you in advance.
Puthick