Hello Bob -
We currently do not have any type of integration with Formstack, that relationship has been nullified. We do not offer any type of embedded form, there are 2 options you can check into we have a API interface that you can use, if you know how to program using (c, .net, php etc) or you can check on the Constant Contact marketplace and see if there are any other folks who offer a free embedded forum.
You mentioned also that you use wordpress, we do not have a plugin that is currently supported by Constant Contact directly however if you google Constant Contact wordpress plugin, you will find the one Katz Webdesign developed for wordpress usage.
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