You can use follow placeholders to add username, name, or usertype into the newsletter sent by the MightyExtensions Massmail Component, the only thing you need is just add the following variables into the letters:
[USERNAME] - add user name to text
[NAME] - add real name
[USERTYPE] - add user's group like Author, Editor, Publisher or any custom user group created with Mighty Permission
[CONFIRMATION] - add special URL which is unique for each user. That is useful if you don't use account activation by e-mail. But user's e-mail address should be confirmed. that will be done by clicking on sent URL. Mighty Registration component shows confirmed e-mails.
[SITENAME] - add Site name
[SITEURL] - add Site URL
[SITENAMEURL] - add linkage Site name
[SITEDESCRIPTION] - add Site description from Global Configuration
Here is a small example:
Hello [NAME].
We are sending you a newsletter because you have subscribed for the newsletters on [SITENAMEURL].
We would like to inform you that we are adding some new features on our web site.
....
Your e-mail is not confirmed, please confirm by click link [CONFIRMATION]