Email notifications are not going out.

When i first installed Course Press, the version was and now the version running is

The email notification was working fine with the prior version but now it does not work, i tried various trigger points like: Inviting student/Instructor from (WP->Users->Add New, Course Press Pro->Student/Instructor->Add New), Create account from login window. But it doesnot send the Inviation/notification out.

Could you please help me with this issue. Thanks so much!