Siteground is upgrading all of its servers from a standard Apache installation to a chrooted Apache installation. This allows much better performance and tightened security.

This transition requires migration from the standard sendmail to mini_sendmail which is better compliant with the new Apache configuration. The new mini_sendmail is very fast and perfectly optmized for the average user. It is compatible with the standard sendmail and can be invoked the same way.

However, it has strict requirements for the email fields. A common problem is to reject mails when the 'to' and 'from' fields contain anything different than emails. For example: 'My test' <test@test.com>. Instead the 'to' field should contain only 'test@test.com'.

This is a known issue in Oscommerce and CreLoaded for example. The code which causes the problem is in the file includes/classes/email.php. There in the function 'send' find the following code:

$to = (($to_name != '') ? '"' . $to_name . '" <' . $to_addr . '>' : $to_addr);

You have to substitute it with:

$to = ($to_addr);

Please make sure that your applications' code is complying with the above requirement in order to use mini_sendmail.