The form in use, does it also collect it's data in the database? If so, the e-mail address could be stored there so should also be possible to export that. Depends of course how you want to do that, through the admin, or on database level.
Regards Robin
Board member, eZ Publish Community Project Board - Member of the share.ez.no team - Key values: Openness and Innovation.
Have a look at project.ez.no and search collectedinformation. THis will allow you export the regular gaterhed data if this form was submitted using the collectedinformaion feature of eZPublish. If it is a custom module, i believe you will have to do the work your self:)
Note, in my experience, this collectedinformation extension does take a lot of time to export large amounts of data, but it will help you:)
