We ran into the same issue so we chose to create our own email submit button. We even allowed our users to enter their email, subject line and body using response boxes. We used the standard button and added the following Javascript on the click event.
var mail;
var vAddress = xfa.host.response ("Please enter the email address","EMAIL RECEIPIENT","firstname.lastname@address.com",0);
var vSubject = xfa.host.response ("Enter subject line","WHAT IS EMAIL ABOUT","Here is the file you wanted",0);
var vBody = xfa.host.response ("Enter body of email","Details", "Here is the file you requested. Thanks for your time",0);
if (vAddress == 0 || vSubject == 0)
{
xfa.host.messageBox ("Email Cancelled","This file will not be emailed",0,0);
}
else
{
mail = "mailto: " + vAddress + "?subject=" + vSubject + "&body=" + vBody;
event.target.submitForm({
cURL: mail,
bEmpty: true,
cSubmitAs: "XDP",
cCharset: "utf-8"
});
}
If you want the body of the email to be blank just remove: + "&body=" + vBody
Hope that helps