1st of all,this is kinda cyber crime ...If you are planning on mail-bombing somebody, there are many things of which you should be aware. First of all, your Internet Service Provider (ISP) will not appreciate you sending mail-bombs through their machine(s). This is because most ISPs don't like abnormal activities taking place from their machine(s) and/or don't want the increased load on *their* system.
If you are mail-bombing a particular person, you are also impacting their ISP. If you fill up that computer with repetitive mail to the person...