user emails to form

I thought the easiest thing would be to have a checkbox in the user table that is either Yes or No called "notifications"

If that checkbox is ticked, it means that that user should be added to the email list.

If that's too easy :) I also have a list of projects (pulled from another table "projects" as value=num, label=title). We could use something like;
$listOptions = getListOptions('accounts', 'project');
$emailProject = "";
if (@$_REQUEST['project']) {
$emailProject = $listOptions[@$_REQUEST['project']];} to identify the specific project being discussed, and then send emails ONLY to those users that have that project selected in their list of accessible projects.

Hi Tim,

So what you need is to select all users who have the notifications check box checked and are selected for the project selected in $_REQUEST['project'] and create a comma-separated list of those emails.

Is that right?

If so, you can use something like this:
$accounts = mysql_query_fetch_all_assoc("SELECT * FROM `{$TABLE_PREFIX}accounts` WHERE notifications = '1' AND project LIKE '%\t".intval(@$_REQUEST['project'])."\t%'");
$emailList = join(",", array_pluck($accounts, 'email'));

Hope this helps

WOW - perfect.

Thanks Jason!