When you encounter deliverability issues at a private domain (or your own domain), you may need to have your sending IP and/or sending domain whitelisted. Private email domains tend to have more aggressive filters in place compared to other large email providers (such as Gmail and AOL).
Let's look at the two ways in which an organization should think about whitelisting.
Whitelisting at your own organization
When you use an outside email server to send email on your behalf, you commonly see deliverability issues when receiving email at your organization. This is because your email server can identify email sent outside of its system (using your sending domain) as being "suspicious" and either quarantine or flag as spam. In order to prevent this from happening, reach out to your IT department prior to sending through MA Enterprise to have them whitelist your IPs.
To find the whitelisting information for your emails, log into your Marketing Automation Enterprise account, select the Tools tab, and scroll to the bottom of the page. Provide your Return Path address and your assigned IP addresses.
Whitelisting at other private domains
If you find that email is not being delivered to the recipients' inboxes at a private domain, you may want to reach out to the domain owner or postmaster to request to whitelist your publish IP and your "from" address.
Keep in mind that whitelisting does not guarantee email will be delivered to the inbox. Whitelisting is done by the email receiver and if the sender is not following best practices, the whitelisting may be ignored.