E-Newsletter

I am trying to install the newsletter plugin. I successfully installed it one time and it worked fine first time. However, I tried to install it on an other wordpress site, using the exact same settings and I get a test bounce error. I have also tried it with several different email services and I get the same bounce error. SMTP error!
Any thoughts, as this is starting to get frustrating.

Also your usage instructions are very, very vague. I would strongly suggest that offer comprehensive instruction manuals with each plugin. This will save you a lot of time with support and save us a lot of frustration.

Thanks
Mark