Inbound Filter - RBL Exception List
The RBL (Real-time Blackhole List) check rejects mail from sender IPs that appear on public spam blocklists. Most of the time this is the right behavior, but legitimate senders sometimes end up on blocklists due to a shared IP, a misconfigured neighbor, or a temporary listing.
The RBL Exception List lets you bypass the RBL check for those trusted senders so their mail is delivered regardless of public blocklist status.
Page Layout
The page header reads Inbound Filter - RBL Exception List.
Search Criteria
A simple search bar:
- One dropdown (default
Total) - A free-text input box
- A blue Search button
Action Bar
A counter (for example TOTAL - 0) is followed by:
| Button | Purpose |
|---|---|
| Add | Open the Add RBL Exception dialog |
| Delete | Delete the exceptions selected by the row checkboxes |
The View 30 dropdown on the right controls page size.
Columns
| Column | Description |
|---|---|
| ☐ | Row selection checkbox |
| Applied To | Recipient or group the exception is scoped to |
| permit Target | The sender IP, domain, or address being excepted from the RBL check |
| Registered By | Administrator who added the exception |
| Registered Date | Timestamp the exception was added |
When to Use
Add an exception when:
- A trusted sender's mail is consistently rejected with an
RBLreason code - You have confirmed the sender is legitimate (verify with the sender's IT contact, not just by reading the message body — phishers can also be RBL-listed)
- The sender's listing is unlikely to be resolved soon (for example a shared hosting IP)
Difference from Other Lists
| List | What it bypasses |
|---|---|
| Allow List | Spam scoring — mail skips the engine entirely |
| Whitelist | The final classification — mail is scored but always Clean |
| Greylist Exceptions | The greylist deferral — mail is delivered without delay |
| RBL Exception | The RBL check only — all other inspections still apply |
The RBL Exception is the narrowest of the four — it removes one specific check rather than waving the sender through all spam controls.
A sender can be RBL-listed because they are actually compromised or sending spam. Confirm with the sender that the listing is incorrect or temporary before adding an exception — do not assume it is wrong simply because the user wants to receive the mail.