SpamRats — Check, Delist & Monitor
Check if you're listed on SpamRats DYNA. Delisting requires valid forward-confirmed reverse DNS. Monitor your IP reputation automatically.
Impact & Usage
Niche list focused on dynamic/residential IPs. Limited adoption beyond certain ISPs. If you're running a legitimate mail server with proper rDNS, this listing is unusual.
Typical users: Some ISPs and email providers; effective at identifying compromised consumer systems on dynamic IPs
What Gets You Listed
IPs with dynamic/residential reverse DNS sending abusive connection volumes or attempts to invalid users; targets compromised home systems
How to Get Delisted
- Check your listing status at spamrats.com/lookup.php by entering your IP address.
- Verify that your IP has a valid PTR (reverse DNS) record that resolves forward to the same IP (forward-confirmed rDNS).
- If your rDNS is missing or points to a dynamic-looking hostname (e.g., pool-192-168-1-1.isp.net), contact your ISP to set a proper static mail server hostname.
- Once your rDNS is correct, submit a removal request at spamrats.com/removal.php with your IP and the corrected hostname.
Expected Timeline
Manual (requires valid rDNS)
Auto-delist: Manual removal request required; must have valid forward-confirmed reverse DNS reflecting a static mail server
Common Causes
- Sending email from a dynamic or residential IP address without proper reverse DNS
- PTR record set to an ISP-assigned generic hostname that looks like a consumer connection
- Compromised home system or IoT device sending SMTP traffic
- Running a mail server on a residential internet connection without static IP assignment
Prevention Tips
- Set up forward-confirmed reverse DNS (FCrDNS) — your PTR record should resolve to a hostname that resolves back to the same IP
- Use a static IP with a hostname that identifies a mail server (e.g., mail.yourdomain.com), not a dynamic pool address
- Do not run production mail servers on residential internet connections
- If you must send from a consumer IP, use a smarthost or relay service instead of direct SMTP delivery
Overview
SpamRats operates the DYNA list, which specifically targets IP addresses that appear to be dynamic or residential connections sending SMTP traffic directly. Unlike traditional spam blacklists that focus on content or volume, SpamRats is primarily concerned with whether the sending IP looks like a legitimate mail server based on its reverse DNS configuration.
The logic is straightforward: legitimate mail servers have static IPs with proper forward-confirmed reverse DNS (FCrDNS) that identifies them as mail infrastructure. Consumer broadband connections have dynamic IPs with generic PTR records assigned by the ISP (e.g., dhcp-192-168-1-100.cable.isp.net). When an IP with consumer-style rDNS sends SMTP traffic, it is almost always a compromised machine — home PCs infected with spam-sending malware, misconfigured IoT devices, or amateur setups that will cause more problems than they solve.
If you are running a legitimate mail server and end up on SpamRats, the fix is DNS-level: ensure your sending IP has a static PTR record pointing to a hostname like mail.yourdomain.com, and make sure that hostname resolves forward to the same IP. Once your rDNS is clean, submit a removal request. SpamRats adoption is limited — mostly ISPs and smaller providers — so the delivery impact is typically low, but fixing your rDNS benefits your reputation across all blacklists and receiving servers.
Monitor Your Blacklist Status
Get alerted the moment your IP or domain appears on a blacklist. Catch listings early, before they impact deliverability.
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