Forward Subscriber emails with a Triggered Send
1. Create a new email.
This can be an HTML paste email because it's only going to contain one substitution string.
2. Type %%_replycontent%% in the body of the email.
%%_replycontent%% is a send time substitution string that puts in the body of the original email plus the Subscriber's reply. This supports up to 10,000 characters including markup. It's only supported with Reply Mail Management.
3. Create a Triggered Send definition with this new email and start it.
4. Go to Admin | Send Management | Sender Profiles.
5. You can either create a new sender profile or modify an existing one.
6. Enter the sender information.
7. Select the checkbox to use the custom settings below for Reply Mail Management.
8. Select the checkbox “Forward using Triggered Send."
9. Select the Triggered Send definition created in step 3.
10. Click Save.
After making these changes, you can test sending an email. Make sure you apply the Sender Profile that you created or updated to it while you're in the Send Wizard or User-initiated Send. After you receive the email, reply to it. When you receive the reply it will now contain the subscriber's reply along with a copy of the original HTML email. This reply is forwarded using the Triggered Send definition that was created in step 3. Therefore, it's sent using your dedicated IP address which, if it's whitelisted, will be successfully delivered to the intended inbox.