First import the contacts from the excel file:
support.microsoft.com/kb/295664
THEN:
First, Select your Contacts. Second, go to Tools, and select Mail Merge.
In the Mail Merge Contacts window choose:
Only selected contacts
All contact fields
If you have your newsletter handy, choose Existing document and then use the Browse button to select it.
In the Merge options section, choose Form Letters as the Document type and Email as the Merge to selection.
Type in the subject of your message when the Message subject line text box appears.
Now click the OK button (CREDIT:https://www.realtown.com/larry2/groups/all-things-outlook/view/10308)
Your other option if you want to personalize it and you have a TON of emails to run down is to create a custom AutoHotkey Script to Personalize each email. (not recommended but fun to watch)