How can I trigger an automatic response whenever a contact replies to a specific email campaign I have sent?
If you wish to have a different auto-response for different campaigns, select Campaigns from the left-hand navigation pane. Your existing campaigns are displayed in the list under the Unsent tab.
Alongside the campaign you wish to set the auto-response for, click on the summary icon. 
The Campaign summary screen is displayed.
Click on Step 4 located in the top right of the screen -- Contacts.
Click on the link Add event triggered emails or auto responders to this campaign located at the bottom of the screen.
The event Triggers screen will be displayed.
From the drop-down against Once a contact has, select the option replied.
The screen will change so you can select the campaign you wish to send.
Select the campaign you wish to send using the drop-down and click on the SAVE button.
The trigger will appear in the list on the event Triggers window.
You can add further triggers if you wish by using the ADD NEW button. When you have finished, close the window.
The trigger(s) you have created will be displayed on the Select contacts and schedule campaign screen at the bottom of the web page.
You can now click on the Save & Continue button.
Important Note
To use this feature, you must first set the campaign you wish to send as a triggered campaign.
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