Email Notifications after reaching the desired size of my Tablespace:

Hi..,
What I 've to do, if I want to get an email notification, after my 
Tablespace(it is not set the autoextend on) is reached the desired size.
Through OEM, I've seen an option i.e  "Thresholds"  Database 
-->Administration-->Storage-->Tablespaces-->Tablespace Name-->DataFile 
Name-->Tablespace Name-->Thresholds  Tab-->Specified Thresholds. 
With this can I get the email Notification..? If not then what is this and how 
can I get the email notifications..? If yes, I 've tried but, there is no 
result, ofcourse I've configured my SMTP well, am getting the mails through my 
database..)

I don't use OEM - I've had enough problems with it in the past that it's left a 
bitter taste probably for the rest of my DBA career and I ended up writing my 
own monitoring framework:

   EVNT - Event Monitoring System For Oracle DB

Recently I gave OEM another shoot and it looked a lot more stable but it still 
failed short for my needs as I have many databases with mixed version to manage 
and I couldn't use ONE OEM installation to do it all.  So for now I am still 
using EVNT and not looking at OEM until we implement Oracle RAC.