Seconded. Also, why re-invent the wheel? You're not DJB, an even if you were, qmail kinda sucks these days. With exim and postfix already out there...I'm struggling to see a point to this.

Want your app to send some mail? Please please please don't try delivering directly. The only people great at this are spammers. Use a real MTA and the mail() function that is built into basically every language.