Hi Vamsi,
This is what happens before an email is sent:
1. NAS AO profile matches an alarm based on criteria you have configured (is this occurring)?
2. When AO profile matches the alarms it sends a message to the bus with subject "EMAIL" (is this occurring?)
you can answer this question by checking Dr.Nimbus for "EMAIL" subject messages:
How to login and use DrNimBUS
https://comm.support.ca.com/kb/How-to-login-and-use-DrNimBUS/KB000057074
3. EmailGtw subscribes to all messages with subject "EMAIL" and then sends an email using the recipient info on the message, and the email server details defined in it (Is this occurring?)
And to start with, check the following articles:
How to configure emails to notify for alarms for servers ?
https://comm.support.ca.com/kb/How-to-configure-emails-to-notify-for-alarms-for-servers/KB000012114
The emailgtw Probe Is Not Sending Emails
https://comm.support.ca.com/kb/The-emailgtw-Probe-Is-Not-Sending-Emails/KB000034398
Emailgtw not working with Exchange Settings
https://comm.support.ca.com/kb/Emailgtw-not-working-with-Exchange-Settings/KB000007812
If these articles do not help you, please let us know, detailing as much as possible, how far did you get with the configuration and what it is not working exactly.