I recommend using one of the following 3rd party services to send campaigns - they are professionals, they know what they are doing, they guide you, they give clients access to live statistics and they are affordable.
1. MailChimp: http://www.mailchimp.com/
2. Campaign Monitor: http://www.campaignmonitor.com
These options above are not the only companies offering sending services, and strickly speaking you do not need to use them - but they are recommended and I do not earn money from you using these services, and I am not affiliated with any of them in any way.