From your description of the symptoms it sounds as though you are adding a
return address to an envelope where the return address already exists. Check
your code.
You will probably find it easier to start with an envelope template which
already has the return address and addressee fields placed. You can create
such a template from scratch or edit one of the samples downloadable from my
web site. Then use an autonew macro in that template to record the
attachment of your data and the execution of the merge.
Create a new document from the template to run the merge.

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Graham Mayor - Word MVP
My web site www.gmayor.com
Word MVP web site http://word.mvps.org
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> I used the macro recorder when performing a mail merge that functioned
> correctly. When I next execute the macro to perform another mail
[quoted text clipped - 4 lines]
> send-to address is printed correctly. Any help will be greatly
> appreciated. Using MSWord 2000.