Receiving email from your forms under Yahoo hosting works a bit different from most hosts.

Under your Yahoo Web Hosting account, go to Web Hosting Control Panel > Create & Update > php/perl mail setup.

In the attempt to restrict spamming, Yahoo requires all PHP mails to specify a from: address that is in your own domain.

Basically this means you need to make sure the form/password forgotten mail adresses are defined to be of your own domain. The basic is that these are send from the Super Admin address which can be anything. Usually builders have a set mail account they use for this.

You can change these by adding the following to your site.php:

define('FORM_BLOCK_SENDER_EMAIL', 'no-reply@yourdomain.com');
define('EMAIL_ADDRESS_FORGOT_PASSWORD', 'no-reply@yourdomain.com');[/code]

The to address you can specify under the form itself.

Yahoo itself gives this as a guide:

http://help.yahoo.com/l/us/yahoo/smallbusiness/webhosting/php/php-17.html