Ok, forget what I said before about the #FILTER rule. Not applicable in this case.
Hmm, as far as I can see there’s no solution without hacking eForm... Here’s a possible solution using the eFormOnBeforeMailSent event...
Just before the line (394 in eform 1.4.2)
Add these 2 lines to eform.inc.php
<?php
$to = formMerge($to,$fields);
if( empty($to) ) $nomail=1;
?>
Then in the onBeforeMailSent event you call this function:
onBeforeMailSentFunction( &$fields ){
$fields['to'] = "NOM_MAILING_LIST-subscribe-" . str_replace("@", "=", $fields['email_visiteur']) . "@domaine.tld";
return true;
}
(oh yes,... I’ve assumed here that the form has a textbox called ’email_visiteur’. Change that in the line above to the name of your textbox.)
The function is placed in a separate snippet which should be called in the same page and before the call to eForm. To get an idea on how to work with eform events look through eForm’s documentation and event examples.