Wait, how does sending little emails can get your server blacklisted? Is it because they don't care about the small guy, or is there some technical reason ?
It's really about how much a false positive affects your IP's reputation.
When you are sending out a lot of email, recipients see a volume of mail. If a few of these get marked as spam, no big deal, you sent out 5,000 mails in an hour, of which 2-3 were marked as a false positive.
If you are running your own VPS you are sending out comparatively fewer mails so the decision on whether you are a spammer or not is made with a lot less information -- and most recipients will assume you are a spammer immediately.
It's mostly because you're not yet proved to be NOT spam. When you start a new mail server on an IP there's zero diference between a legimate email server and a spamhost. Your IP will not be in spamhaus and other blacklists, but you might get stuck in McAffee and other more enterpricey filters, especially if some other IPs in your subnet are known to send spam.
