Cannot send email with FB7

My company recently acquired a license of FB 7 in order to migrate our existing build process.
All the tasks seem to work fine, except the Send Email task. It throws the next exception:
 

9/6/2011 3:33:51 PM : 535 5.7.3 Authentication unsuccessful.
Unable to Send Message (Connect)
Authentication unsuccessful.

Do you have any idea on how to solve this issue?
I tested the same task (with the same configuration) on FB 4 and it works fine.
 

You haven’t given us much to work with. What settings do you have on the action? What mail server are you connecting to?

I’ve already solved the problem, it was caused by an incorrect text set on the sender address of the Send Email Task settings (perhaps FB 4 was not validating or using it, but FB 7 now does and Exchange Server was not resolving that text to a valid address).

Thanks for your help.

Brgs,
Mario Covarrubias.