If you search the constant contact FAQ for "Can I add a PDF to my email?" you'll see a few suggestions, none of them great. For a Publisher file, try saving the publication as a web page. Then open the web page, right-click and select View Source (for Internet Explorer.... not sure about other browsers). Cut and paste the source code into the advanced editor in Constant Contact. You may need to tweak it to get it to look right. Any web page editor will allow you to create or edit a constant contact email generated this way.
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