Assuming that you are using Publisher 2003, then you will not get the same
results as a program that is specially designed for a purpose such as
Constant Contact. However, you can get some pretty good results. Reference:
Create and send e-mail publications using Publisher:
http://office.microsoft.com/en-us/publisher/HA010743381033.aspx

Some keys. Start with one of the email formatted templates. Don't try to
send 8.5 inch wide emails. You can only send one page...keep it small, and
link to other content on your website. You can send it as an image or HTML.
Go to tools > options > Web Tab and uncheck or check "send entire
publication as an image...". Note if you do send it as an image the file
size is likely to be pretty large, which is going to upset many of those
people that you send it to. Check the file size before you start sending it
to people with a dial up modem especially. If the recipient has their email
client set for plain text, they will not be able to read the html version.
Send it to yourself and see how big of file it is.

You will not be able to merge emails with particular addresses with
Publisher 2003, but you can with Pub 2007. You can email a Pub 2003 version
to a group from Outlook or OE, but I would do that after sending a copy to
yourself, and then forwarding that to your group.

In general, you might want to consider converting your newsletter to PDF and
attaching it. It will be a smaller file size than sending as an image, your
content will look exactly as you intended, and most people do have the Adobe
Reader installed.

DavidF