I cannot send messages with TheBat anymore. It says certificate is expired. So what to do then? Where and how to get it working?

there is a log:
>22/08/2007, 21:05:39: SEND - Certificate S/N: ********, algorithm: RSA (1024 bits), issued from 21 Aug 2006 to 21 Aug 2007, for 1 host(s): smtp.gmail.com.
>22/08/2007, 21:05:39: SEND - Owner: Google Inc, smtp.gmail.com.
>22/08/2007, 21:05:39: SEND - This certificate is self-issued.
!22/08/2007, 21:05:39: SEND - TLS handshake failure. Invalid server certificate (This certificate has expired).