Mail Log Analysis

I recently set-up AWStats to analyze my mail logs. I’ve had sporadic problems with my mail server (people not recieving emails I’ve sent, emails to me getting lost, etc) and I decided I need to keep a closer eye on it. Anyway, after 2+ days of analysis it seems that 7 out of 604 emails failed to transmit successfully. That’s about 1.1%. Is this acceptable? Terrible? I have no idea, but I’m definitely going to start poking around to see what’s wrong. In my naive mind, zero failed emails should be the goal.