queues and things

[User At]

I currently have a deamon that reads a data from a serial port, and based  
on certain data it sends out alert messages (sms,email,etc). The problem I  
have is that sending alerts requires a bit of time (about 30 seconds), so  
I use non-blocking queues which works fine. But, when a signal to  
"terminate" is sent to the daemon, only the first entry in the alert queue  
is completed before exit. Is there way to get all the items on the queue  
to be executed before the exit?