E-mail for unread messages ON by default?

I'm not a programmer, but I took a look at privatemsg.module and found the following:

        $form['privatemsg_settings']['privatemsg_mailalert'] = array(
            '#type' => 'radios',
            '#title' => t('Receive e-mail for unread messages'),
            '#options' => array(PRIVATEMSG_MAIL_NONE => t('Never'), PRIVATEMSG_MAIL_DIGEST => t('Daily'), PRIVATEMSG_MAIL_INDIVIDUAL => t('Every message')),
            '#default_value' => isset($edit['privatemsg_mailalert']) ? $edit['privatemsg_mailalert'] : PRIVATEMSG_MAIL_NONE,
            '#description' => t('Select when to receive e-mail notification for unread messages.')
            );

In the default_value line, if I simply change PRIVATEMSG_MAIL_NONE to PRIVATEMSG_MAIL_INDIVIDUAL, I believe it would default to send e-mail alerts for every new PM. I further assume this won't make any setting changes to existing users.

Could someone confirm this before I hack the mod?

Is it possible that this change would change the setting for existing members and not just the new ones? I had been going through my members switching this to "every message" (of course the user could switch it back, my users just aren't used to getting online to see if they have any PMs) and now most of the accounts seem to be set that way since I made the change in the module. Saves me a lot of work, but I wasn't expecting that to happen either.

fuzzy_texan --

I think you are right. It did seem to switch my existing users to send e-mails when new PMs arrive, but I don't think it is actually working unless you re-save their profile or change the setting and change it back.

I poked around in the database and the settings for the mail alerts isn't set for any of those options until the profile is edited in some fashion. So, I think I'm still going to have to go into each users account and mess with their settings in order to get those e-mail alerts on.