iRule to Offload Secure SMTP

I've seen the iRule in the CodeShare section on using the LTM as an SMTP proxy, but has anyone given any thought to converting it to handle Secure SMTP as well? Can anyone go over the sequence of events surrounding STARTTLS and whether I could easily capture the switch from unencrypted to encrypted and handle it correctly?

 

 

Thanks! Go BEARS!

 

 

Dave