Attempt to Instantiate Missing Class

BACKGROUND - I copied the PRD database for a site to the DEV install and started getting a fatal error that a class could not be found. Error was from mailsystem.module line 293

PROBLEM - Attempting to instantiate a class without confirming that it has been defined.

SOLUTION - Added a class_exists()

// ORIGINAL
      if ( ($autoload || preg_match('/MailSystem/', $classname))
        && ($object = new $classname)
        && ($object instanceof MailSystemInterface)
      ) {

// FATAL ERROR WENT AWAY 
      if ( ($autoload || preg_match('/MailSystem/', $classname))
        && class_exists( $classname )
        && ($object = new $classname)
        && ($object instanceof MailSystemInterface)
      ) {