Well, I am a bit confused because this forum is for the FCKeditor provider. I will try to answer you if your promise me to chose a correct forum the next time. hehe
About the smpt server:
- You can use whatever smtp sever you want. Most providers gives their own users access to a master smtp server. Check with your IP about this option
- XP and W2K,W3K server include a smtp server, so there is no need of a bigger software (Depending of your needs off course)
- You can use whatever server you want as it meets the standards.
About the URLs in mails.
Dotnetnuke generates the email by using the original site name. If you register to site www.a.com, the the URL will be generated with www.a.com inside the email. Most modules work this way, but I cannot be sure about all modules
Note: You need FCKeditor to generate emails that include a FULL url. from the standard newsletter module. otherwise your DNN will include only relative paths. please note that there are more specific modules that also generate full paths.