Which feature in the email pipeline is available only in the outgoing mail policies?

The feature that is available only in the outgoing mail policies in the email pipeline is the "Bounce Verification".

Here's how it works:

1. Outgoing mail policies are rules that apply to emails being sent out from your network. These rules can help control what information is allowed to leave your network via email.

2. One of these rules is Bounce Verification. This feature helps protect your network from bounce attacks, where spammers can use your server to bounce spam off to other servers, making it look like the spam came from your network.

3. When Bounce Verification is enabled, your server adds a verification code to each outgoing message. If a bounce message comes back, your server checks that code. If the code is present and correct, the bounce is accepted. If not, the bounce is rejected.

4. This feature is typically only found in outgoing mail policies, as it is specifically designed to protect your network from being misused by spammers.