I used to do buttloads of SharePoint development since 2007 to 2013. One of the stuff I used a lot and an now putting it here so I remember it is the SPUtility.SendMail() function. It basically one of those undocumented features that I used a lot. It may be documented now but here is goes anyway:
var headers = new StringDictionary(); headers.add("to","firstname.lastname@example.org"); headers.add("cc","email@example.com"); headers.add("bcc","firstname.lastname@example.org"); headers.add("from","myAddress@test.com"); headers.add("subject","How to use SendEMail from SPUtility"); headers.add("content-type","text/html"); //This is the default type, so isn't neccessary. var bodyText ="This is the body of my email, in html format.“; SPUtility.SendEmail(web, headers, bodyText);
This will enable you to send an email with the SMTP server you configured in on SharePoint Central Administration.
Hope this helps.