ExchangeIt isn't so bad
Other programs, which earn their developers lots and lots of money, appear to do much worse even after years and years of effort.
Disclaimer: Okay, ExchangeIt 1.0 was kind of bad, but it was a 1.0. And okay, I'm still not sure why we decided to write a high-performance, high-reliability network server application in perl. But we actually made it work in the end. I'm kind of impressed.