I think many guys faced this problem.

I am facing very small problem, My workflow i almost completed. but
email functionality is not working.
for each task assgined to user, need to send an email to say task
assigned to him.
but in my workflow history,after each task created, the error message
shown like below.

The e-mail message cannot be sent. Make sure the outgoing e-mail
settings for the server are configured correctly

i configured exchange server as smtp server and correct email address
given in the central admin, out going email settings.
nothing is wrong in configuration, but it still not sending emails.
sending email is the highest priority in workflows.