emailbot

i made my first vb program titled "emailbot". i found vb quite easy to learn because i already knew c++ and the main difference i thought is the syntax. anyway emailbot is a small program that loads a txt file specified by the user and emails all the emails in that txt file a message that you want, and u can have attatchments if u would like.
a question i have:
how could i make it better?
how do other email spammers work? do they do it differently?