To setup mail alerts in OEM 11g,
1. First step would be to set the Notification Methods.
Goto Setup (On Right top of OEM UI)->Notification Methods (On left Panel).
It should give you page to setup Mail Server for notifications
Outgoing Mail (SMTP) Server - smtp.mycorp.com
User Name - myadmin
Password - ******
Confirm Password - ******
Identify Sender As - Enterprise Manager
Sender's E-mail Address - firstname.lastname@example.org
Use Secure Connection - No : E-mail is not encrypted.
SSL: E-mail is encrypted using the Secure Sockets Layer protocol.
TLS, if available: E-mail is encrypted using the Transport Layer Security protocol if the mail server supports TLS. If the server does not support TLS, the e-mail is automatically sent as plain text.
2. Second step would be to setup email for an OEM user
To receive email notification, specify email address(s) on Preference page.
Goto Preferences (On Right top of OEM UI)->General (On left Panel).
Add email address(s) and Test it(them).
3. Third step is to select a Notification Schedule [Optional for this usecase]
Goto Preferences (On Right top of OEM UI)->Notification Schedule(On left Panel).
By default, for the first time, 24x7 weekly notification schedule is set automatically.
A notification schedule is a repeating schedule used to specify your on-call schedule—the days and time periods and e-mail addresses that should be used by Enterprise Manager to send notifications to you. Each administrator has exactly one notification schedule.
4. Fourth step is to create a Notification Rule for WebLogic Domains/Servers and subscribe to it, to receive an e-mail
A notification rule is a user-defined rule that defines the criteria by which notifications should be sent for alerts, policy violations, corrective action, execution status and job execution status.
a. Goto Preferences (On Right top of OEM UI)->Notification-> Rules(On left Panel). [For a super administrator, it will be display Rules while for a normal administrator, it will be My Rules]
b. Click Create button.
It will display "Create Notification Rule" pages. Enter the required information on each page to create your notification rule.
e.g. In General tab, Provide rule
-name as "WebLogic Server Availability and Critical States"
-Description as "WebLogic Server Availability and Critical States"
-Select 'Make Public' check box
-Select 'Target Type' as "Oracle Weblogic Server"
-Select appropriate radio button to apply rule to all Weblogic Servers or selective Weblogic Servers.
In our case, lets select 'Apply rule to all Oracle WebLogic Server targets' radio button.
On Availability tab,
Select 'Up' and 'Down' Checkboxes (and any other status that you are interested in)
If you have chosen any metrics, then add those metrics under Metrics tab.
One can add policies/jobs via Policies/Jobs tabs.
On Actions tab,
Select 'E-mail Notification', 'Send Me E-mail' checkbox.
Select OK Button.
Note: Notification rules allow you to choose the targets and conditions for which you want to receive notifications from Enterprise Manager. These notifications include e-mail, SNMP traps and running custom scripts.
For more details about various Notification options and Out of Box rules etc., pl refer