I need to accomplish the assignment below every month, with a different list
eachtime, what is the right way to do it?

I DO KNOW the basics, but I'm having trouble with the finer points the
best way to use email addresses that are not initially in Outlook, and the
best way to use TO: and BCC: and distribution lists effectively to make the
email look correct at the recipient's end.

I'm starting with a .TXT file in Windows but it's external from Outlook.
The file contains names and email addresses, approx 25 to 50 names. Here is
a sample of the .TXT file (my real file is fixed-column, but it might not
appear that way in this message)

Miles Smith
Michael Dell
Steve Ballmer
etc

I want to send the same email message to everyone on the list. At their
end, the received message should end up looking something like this, with
either their own name in the "To:" filed, or a generic group or DL name.
===========================================
From: Becky
To: Miles Smith
Subject: Your insurance premium is due next month

This is just a friendly reminder that blah blah blah
===========================================
OR
===========================================
From: Becky
To: Renewal Customers
Subject: Your insurance premium is due next month

This is just a friendly reminder that blah blah blah
===========================================

I know one way to import the file into an Outlook distribution list, but
what is the best or correct way? Or, if I just copy the contents on to the
BCC line, what should I enter on the TO: line? I don't want the message to
look like

From: Becky
To:
Subject:
etc