html newsletter sending problem
 

i had create a newsletter in html format but unable to sending it to my customers, they are getting only the html code itself.

You need to use MIME headers to set the content-type to text/html. (Search www.rfc-editor.org for MIME). How you do this depends on how you are constructing your email message and how you are sending it.

And preferably include a plain-text version of the newsletter as well, for those who don't want to run the inherent risks from HTML email.