CWP forces the @ prefix for sender blacklist entries, but Postfix works without

Hello CWP Support and Community,

I'm using CWP Control Panel with Postfix 3.4.8 on AlmaLinux 8.

CWP's web interface requires the `@` prefix when adding a domain to the sender blacklist. For example, the interface requires:

```text
@greenstreembv.com
```

However, I tested both formats directly on my server, and the domain entry without `@` is the one that correctly blocks the sender.

My Postfix configuration is:

```text
smtpd_sender_restrictions =
    check_sender_access hash:/etc/postfix/sender_whitelist,
    check_sender_access hash:/etc/postfix/sender_blacklist
```

When the blacklist contains:

```text
greenstreembv.com REJECT
```

Postfix correctly rejects a sender such as `noreply-wetransfer.pt@greenstreembv.com`.

The rejection was confirmed using both `swaks` and Telnet. The SMTP transaction returned:

```text
554 5.7.1 <noreply-wetransfer.pt@greenstreembv.com>:
Sender address rejected: Access denied
```

I also confirmed that the hash map returns `REJECT` for the domain key.

**My questions are:**

1. Why does the CWP interface require the `@` prefix for domain blacklist entries?
2. Is CWP expected to translate this format internally when generating `/etc/postfix/sender_blacklist`, or is the `@` prefix written directly to the Postfix access map?
3. Is this behavior intentional, or could it be a bug in the CWP interface or its blacklist-generation mechanism?
4. What is the officially recommended format for domain blacklist entries managed through CWP?

I would like to manage the blacklist through the CWP interface without having to edit the generated Postfix file manually or risk losing the rules after a configuration update.

Thank you.