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Go to CRM > Campaigns > Then click edit on the campaign you wish to set the SMTP account on.
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Scroll down to the Auto-Responders Email section and click on the green + button to add an SMTP accountcreate an Auto-Responer.
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This will bring you to a dialogue box in which you can choose the SMTP you would like to use as well as the event name, the products, email subject, and which billing cycle you would like it to fire on.
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