WinCCFlex2005 email notification of alarms

Hello,

I have been trying to set this option in one WinccFlex project. I set up SMTP both in the project and in WinCCFlex internet settings of my laptop (where the RT is running at the moment) but I always have warrning 70037 cannot send e-mail. I think I did everything by the book. I checked SMTP with our IT guy and it is OK. HTML browser which I put to try RT is working.
What can be wrong with email?

Thanks in advance