There's a fine line between ending up in the junk folder, and creating an e-mail campaign that people are interested in reading. When used properly, with an understanding of marketing, e-mail campaigns are some of the most successful conversion tools ever. At Nenen, we like to understand what your expected results are from your marketing campaigns – are you looking at prospective or existing clients? What sort of message are you trying to send? What part of your business are you looking to boost?
Spamming is sending unsolicited commercial email using broadcast methods to multiple recipients, without first establishing a relationship with them (getting permission) and without regard to their categorical interests (untargeted). Long-story short – it's totally useless.
Permission-based e-mail is a cost-effective method of marketing that operates on the premise that the recipient of your message has an established relationship with you and has previously indicated interest in your product. There's no point selling a pen to someone that doesn't want to buy a pen.