Open your Pub file. Go to Tools > Options > Web tab and under E-mail options
uncheck: "Send entire publication....as a JPG image...".

Also you may need to change your layout or formatting to prevent the text
from being converted to an image. There are a number of things that can
cause that including using a non-web friendly font. Reference: Tips and
troubleshooting for sending a publication page as an e-mail message:
http://office.microsoft.com/en-us/publisher/HP010390591033.aspx?pid=CH062524821033

And though you don't want to send as an attachment, if you want to make sure
that your newsletter is delivered in exactly the way you designed it, then
send it as an attached PDF. If you have Pub 2007, that option is built in.
Otherwise download and install www.primopdf.com which is a free pdf tool.

DavidF