FREE SMTP RELAY FINDER Automated Scanner • Open Relay Detection • Authentication Testing • Speed Verification
RELAY FINDER: Automated SMTP relay finder tool. Scans IP ranges for open relays, tests authentication, measures speed, and outputs clean working list. Includes 50K IP seed list of known mail server ranges to speed up scanning.FEATURES
| Feature | Description | Performance |
| Mass scan | Scans /24 subnets for open port 25, 587, 465, 2525 | 10K IPs/min per thread |
| Banner grab | Identifies SMTP server software and version | Instant |
| Auth test | Tests: none, LOGIN, PLAIN, CRAM-MD5, NTLM | 2 sec per relay |
| Relay test | Attempts to send test email to external domain | 3 sec per relay |
| Speed test | Measures: connection time, auth time, send time | 5 sec per relay |
| Blacklist check | Checks IP against 40+ DNSBLs | 1 sec per relay |
| Export | Output: CSV, TXT, JSON, OB2 proxy format | Instant |
| Scheduler | Automated scanning on a timer | Configurable |
HOW TO USE
Code:
1. Download and extract SMTP_Relay_Finder.7z
2. Edit targets.txt with IP ranges (one per line):
192.168.1.0/24
10.0.0.0/8
Or use included seedlist (50K mail server IPs)
3. Configure scan settings:
- Threads: 100 (default, increase for faster scans)
- Ports: 25,587,465,2525 (or custom)
- Timeout: 5 seconds (increase for slow servers)
- Test email: [email]test@example.com[/email] (customize)
- Proxy: optional (scan through SOCKS5)
4. Run:
SMTPRelayFinder.exe --input targets.txt --output relays.txt
5. Monitor progress:
- Scan speed: ~50K IPs/min on 100 threads
- Found relays displayed in real-time
- Progress bar + ETA
6. Results:
Successful relays saved to relays.txt:
smtp.server.com:25:auth:none:50ms
mail.company.org:587:user:pass:120ms
Failed/unreachable: saved to failed.txt (optional)
7. Verify found relays:
Use included verify tool: SMTP_Verifier.exe --input relays.txt --output verified.txt
Re-tests each relay with actual send attempt
Included seedlist: 50,000 IPs of known mail servers (MX records from Majestic Million)
Expected results: ~100-500 working relays from seedlist scanDOWNLOAD
Code:
MEGA: [URL="https://mega.nz/file/BlackSec_SMTPRelayFinder_2026"]File on MEGA[/URL]
Size: 15 MB | Password: SMTPFinder2026
Includes: Windows binary + Python source + seedlist (50K IPs) + IP range generator + documentation