outlook forms – email address field

I set up a custom contact form to assemble a list of members. I want to use the information to send out (group)emails.
The contact folder is split into five subfolders, the custom form published to each. Storing the information works fine, extracting mailing labels etc, too.

I cannot acces the information from the “to” button of a “new message” nor can I “right click” and “New message to contact”.
I get a failure message saying “this contact does not have an email address …” and it adds the name instead of the email which is stored definitely in there. I think it might have something to do with the “Field value” of the custom “text field” but have actually no idea how to fix it.
HELP is most apreciated.
Cheers