Give the gift of Drupal. All merchandise is 50% off through 2016.
Warning: class_implements() [function.class-implements]: Class MailsystemDelegateMailSystem does not exist and could not be loaded in drupal_mail_system() (line 276 of /XXX/includes/mail.inc).
Class MailsystemDelegateMailSystem does not implement interface MailSystemInterface
There is a typo in the .info file - the case of the actual filename is different to what is there, and on our systems that stops the class being loaded when needed. The attached patch fixes this.