Sending Emails from the Portal is a key functionality for Collaboration and certain KM services. Below is a step by step configuration of Email in Portal.
Create the system Object for the Microsoft Exchange ServerUse the SMTP server address
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Create the Alias for the system object
Configure the email service
System Administration > System Configuration > Content Management > Global Services > Mailing Services > check for the tick sign in the Active section.
Creating an Email Transport
System Administration > System Configuration > Collaboration > Transports
System Administration > System Configuration > Collaboration > Transports > Mail Transport > Click New > use the SMTP address
Make sure you have the collaboration link activated on the portal to test this functionality.
Check your email for the response..
I hope the above configuration was simple enough....