{"id":1002,"date":"2026-09-22T09:30:59","date_gmt":"2026-09-22T09:30:59","guid":{"rendered":"https:\/\/smppcenter.com\/kb\/?p=1002"},"modified":"2026-09-22T09:31:01","modified_gmt":"2026-09-22T09:31:01","slug":"smpp-server-rejection-rules-block-traffic","status":"publish","type":"post","link":"https:\/\/smppcenter.com\/kb\/smpp-server-rejection-rules-block-traffic\/","title":{"rendered":"How to Block Unwanted SMPP Traffic with SMPP Server Rejection Rules"},"content":{"rendered":"\n

Rejection Rules stop unwanted messages at the door. When one of your SMPP clients sends a submit_sm<\/code>, the platform checks the sender ID and destination number against your rules. If they match, the request is refused in the submit_sm_resp<\/code>, so the message is never queued, routed or sent to a vendor.<\/p>\n\n\n\n

This matters for aggregators because anything that reaches a vendor costs you money and can risk the route. Blocking at submission is the cheapest place to stop it.<\/p>\n\n\n\n

Where to find it<\/h3>\n\n\n\n

Sidebar \u2192 SMPP Server \u2192 Rejection Rules<\/strong>, then Manage SMPP Server Rejection Rules<\/strong>.<\/p>\n\n\n\n

Create a rule<\/h3>\n\n\n\n
    \n
  1. Click + (Add)<\/strong>.<\/li>\n\n\n\n
  2. UserName:<\/strong> leave it as Universal<\/strong> to apply to all your SMPP clients, or pick one client.<\/li>\n\n\n\n
  3. Name:<\/strong> something descriptive, e.g. Block spoofed bank headers \u2013 client XYZ<\/em>.<\/li>\n\n\n\n
  4. SenderName Match Criteria:<\/strong> exact match, starts with, ends with, contains, and more.<\/li>\n\n\n\n
  5. SenderName Details:<\/strong> comma-separated values.<\/li>\n\n\n\n
  6. Series Match Criteria<\/strong> and Series Details:<\/strong> the destination number patterns, comma-separated.<\/li>\n\n\n\n
  7. Status:<\/strong> ENABLED.<\/li>\n\n\n\n
  8. Click Save Changes<\/strong>.<\/li>\n<\/ol>\n\n\n\n

    Typical uses<\/h3>\n\n\n\n
    Scenario<\/th>Rule<\/th><\/tr><\/thead>
    A client tries to send with a brand’s sender ID they aren’t authorised for<\/td>Client-specific, SenderName exact match<\/strong> on that header<\/td><\/tr>
    Traffic to a destination range you have no route or licence for<\/td>Universal, Series starts with<\/strong> that prefix<\/td><\/tr>
    Test\/junk traffic hitting a known dummy range<\/td>Universal, Series starts with<\/strong> the range<\/td><\/tr>
    A compromised client account pushing lookalike sender IDs<\/td>Client-specific, SenderName contains<\/strong> the brand string<\/td><\/tr><\/tbody><\/table><\/figure>\n\n\n\n

    Things to know<\/h3>\n\n\n\n