No Reply To address selected: If you send an email without designating a Reply To address, replies to the email (including out of office notifications) will be sent to whoever the email initially appeared to come from. The original sender could be a specific user in your account, a general email address or the prospect's assigned user. You can select the sender of the email under the Sending tab in Email Flow when creating emails and email templates.
For example, within your email template if you selected the email to come from Pardot (email@example.com) all replies to that particular email would be sent back to firstname.lastname@example.org. If you selected the option of "Make the "From" address the prospect's assigned user, if available" and a particular prospect was assigned to the user John Doe the prospect would receive an email from John Doe (John.Doe@pardot.com) and all replies to that particular email would be sent back to John.Doe@pardot.com.
Reply To address is selected: If you send an email and specify a Reply To address that is different than the original sender address, replies to the email (including out of office notifications) will be sent to the designated Reply To address. This applies no matter what type of sender (specific user, general email address or assigned user) that you select too. You can specify a Reply To address for an email under the Sending tab of Email Flow.
Please note that while we request your prospects' email servers and email clients to send their replies to the original sender or Reply To address as you specify, it is ultimately up to the prospect's email server (for out of office and bounce notifications) or email client (for replies from the prospect's inbox) to make it happen.