It is said that mass email is allowed to send 250 mails per call and  up to 1000 mails per day.

But I found the article on the page 181 of  the book "Development with the Force.com Platform" by Jason Quellette

saying  "You can reach 2,500 recipients using the MassEmailMessage ". On this book  said  " 250 recipients times the 10 invocation maximum".

Is it true we can send 2500 mails per pay ?

Any suggestion appreciated.

     Yoshio Takemura