I have an email service which parses responses if my customers send emails to the Salesforce generated email.
I want to know whether it is possible to send out emails from the Salesforce generated email address (using our email templates)?
If you are sending the email from Apex, you would want to set the Email service address as the reply-to address of your outgoing email.
If you want to set up the generated email service address as an Organization-Wide Email address you can use to send Email Alerts and other emails from, you need to follow these steps.
I have an email service that receives emails from users and parses them into the database.
We set up an Organisation-Wide email address whose address was the email service's inbound address. We have a workflow that fires an email out to the user, using the org-wide email as the "sender" address, and the user replies to the email.