If you a big mailing list of your website users and if you are thinking to send a promotional offer or newsletter or catalog you need to be very careful. If you frequently send mails to your users they get irritated and may un-subscribe from your site’s mailing list. You also want to avoid any problems with the law and your internet service provider (ISP). There are many things you have to keep in mind. email marketing has become very popular because of its low cost and with you approach you can easily reach the end users. It is very important that you keep your list clean and organized. Always provide an unsubscribe feature in your site and an unsubscribe link in your mails. This will give a very good impression for your users.