Topic: leavemessage.php error on v1.6.4

[crazy]

Hi there,
i downloaded the v1.6.4 and it is all working fine, except the "leave a message" when operator is not online.... after i click "leave a message" on the generated button.... and i filled up all the form, email,name &question..... then submit..... and it show leavemessage.php encounter HTTP500 error... and it seems like it cannot send the email...

but i used the "email chat history" function, and the email is working fine, and got the email message in my inbox.

please advice what is the problem, all the php file is original, only changed the "config.php" param on my side.
thank you very much

--Crazy